America's red gold: multiple lineages of cultivated cochineal in Mexico

Cultivated cochineal (Dactylopius coccus) produces carminic acid, a valuable red dye used to color textiles, cosmetics, and food. Extant native D. coccus is largely restricted to two populations in the Mexican and the Andean highlands, although the insect's ultimate center of domestication remains unclear. Moreover, due to Mexican D. coccus cultivation's near demise during the 19th century, the genetic diversity of current cochineal stock is unknown. Through genomic sequencing, we identified two divergent D. coccus populations in highland Mexico: one unique to Mexico and another that was more closely related to extant Andean cochineal. Relic diversity is preserved in the crops of small‐scale Mexican cochineal farmers. Conversely, larger‐scale commercial producers are cultivating the Andean‐like cochineal, which may reflect clandestine 20th century importation.     

Developmental timing of extreme temperature events (heat waves) disrupts host–parasitoid interactions

1. When thermal tolerances differ between interacting species, extreme temperature events (heat waves) will alter the ecological outcomes. The parasitoid wasp Cotesia congregata suffers high mortality when reared throughout development at temperatures that are nonstressful for its host, Manduca sexta. However, the effects of short‐term heat stress during parasitoid development are unknown in this host–parasitoid system.
2. Here, we investigate how duration of exposure, daily maximum temperature, and the developmental timing of heat waves impact the performance of C. congregata and its host¸ M. sexta. We find that the developmental timing of short‐term heat waves strongly determines parasitoid and host outcomes.
3. Heat waves during parasitoid embryonic development resulted in complete wasp mortality and the production of giant, long‐lived hosts. Heat waves during the 1st‐instar had little effect on wasp success, whereas heat waves during the parasitoid''s nutritionally and hormonally critical 2nd instar greatly reduced wasp emergence and eclosion. The temperature and duration of heat waves experienced early in development determined what proportion of hosts had complete parasitoid mortality and abnormal phenotypes.
4. Our results suggest that the timing of extreme temperature events will be crucial to determining the ecological impacts on this host–parasitoid system. Discrepancies in thermal tolerance between interacting species and across development will have important ramifications on ecosystem responses to climate change.

     

Dactylopius opuntiae,a new prickly pear cactus pest in the Mediterranean: an overview

The Opuntia cochineal scale or false carmine cochineal scale, Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae), is spreading rapidly in many countries, especially in the Mediterranean basin, where it has become a serious pest of prickly pear crops, Opuntia ficus‐indica (L.) Miller (Cactaceae). This crop is an important food resource both for humans and livestock. The cochineal was originally used as a biological agent to control cactaceous weeds in many countries where Opuntiaceae had been introduced. Currently, in some countries where the prickly pear is no longer considered a weed but a productive crop, as in the Mediterranean area, D. opuntiae has changed its role from a highly prized biological control agent to the status of serious pest. This paper provides an overview of the current knowledge on D. opuntiae for farmers and stakeholders in order to indicate the most appropriate way to limit or counteract the spread of this pest especially in new cultivated areas.     

Comparative toxicity of different chemical and biological insecticides against the scale insect Dactylopius opuntiae and their side effects on the predator Cryptolaemus montrouzieri

The contact toxicity of various chemical and biological pesticides for the first and second instar nymphs and adults of the Opuntia cochineal scale insect Dactylopius opuntiae and the predator ladybird Cryptolaemus montrouzieri was determined under Morocco semi field conditions. d-limonene (60?g/l) at 100 and 150?cc/hl, mineral oil (780?g/l) at 2400?cc/hl and malathion (500?g/l) at 300?cc/hl caused the highest mortality (99–100%) among first instar nymphs of D. opuntiae 24?h after treatment. d-limonene (60?g/l) at 150?cc/hl caused greatest mortality (99%) in second instar nymphs. The highest mortality (99%) among adult female D. opuntiae was observed 120?h after treatment with d-limonene (60?g/l) at 150?cc/hl and mineral oil (780?g/l) at 2400?cc/hl. For the predator C. montrouzieri the highest mortality (92–97%) among adults 24?h after treatment was caused by malathion (500?g/l) at 100, 200 and 300?cc/hl and alpha-cypermethrin (100?g/l) at 75, 150 and 225?cc/hl. The most harmful pesticides to C. montrouzieri larvae 24?h after treatment were malathion and alpha-cypermethrin with mortality rates of 89–95%. Mortality in larvae ranged from 87 to 100% 120?h after treatment with chlorpyriphos-methyl (480?g/l) at 75, 150 and 225?cc/hl and spinosad (480?g/l) at 100, 200 and 300?cc/hl. d-limonene (60?g/l) at 50?cc/hl and mineral oil (780?g/l) at 1000?cc/hl had the least impact on C. montrouzieri adults and larvae, causing mortality of 11 and 15%, respectively, 120?h after treatment. d-limonene (60?g/l) and mineral oil (780?g/l) may therefore be viable alternatives to others high-risk chemical pesticides. These two biological insecticides are effective in controlling the Opuntia cochineal scale insect but have little adverse impact on the predator C. montrouzieri.     

Testing the hypothesis that a cochineal insect species (Hemiptera: Dactylopiidae) may have been displaced by a congeneric biological control agent from a different cactus host

In 1913, a cochineal insect species, Dactylopius ceylonicus (Green) (Hemiptera: Dactylopiidae), was released in South Africa as a biological control agent against drooping prickly pear Opuntia monacantha. Later, in 1938, Dactylopius opuntiae (Cockerell) was used, together with several other biological control agents, to suppress populations of mission prickly pear, Opuntia ficus-indica. Both programmes achieved considerable success in alleviating these weed problems. In common with some other cochineal insect species, D. opuntiae is oligophagous which has led to allegations that it has competitively displaced D. ceylonicus on O. monacantha in South Africa. An investigation into this supposition showed that D. ceylonicus is still present at all of the seven sites where O. monacantha was monitored and that D. opuntiae was not found to occur on O. monacantha at any of the sites. Although D. opuntiae is able to use both O. monacantha and O. ficus-indica as hosts, under laboratory conditions its performance (developmental duration, survival and body mass of the females at maturity) was significantly inferior to that of D. ceylonicus on O. monacantha. These observations show that there is no evidence of the actual or potential displacement of D. ceylonicus by D. opuntiae on O. monacantha.     

Weed biological control in the European Union: from serendipity to strategy

Biological control of weeds is a globally recognised approach to the management of some of the most troublesome invasive plants in the world. Accidental introductions of agents accounted for all weed biological control agent establishments in the European Union until 2010, but these examples include some current or emerging control successes both large and small, from the redistribution of the weevil Stenopelmus rufinasus Gyllenhal (Coleoptera: Curculionidae) for the control of small outbreaks of Azolla filiculoides Lam. (Azollaceae), to the large scale control provided by the cochineal insect Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae), used against some problematic prickly pears (Opuntia spp. (Cactaceae)), and the ragweed beetle Ophraella communa LeSage (Coleoptera: Chrysomelidae), against common ragweed, Ambrosia artemisiifolia L. (Asteraceae), which are providing benefits to an increasing number of Member States of the European Union. Recent programmes involving the intentional introduction of biological control agents against target weeds including Fallopia japonica (Hout.) Ronse Decr. (Polygonaceae), Impatiens glandulifera Royle (Balsaminaceae) and Acacia longifolia (Andrews) Willd (Fabaceae) show a shift from luck to judgement in the European Union. The inclusion of new weed targets on the European Invasive Species Regulation should lead to a growth in the profile and use of biological control which would be assisted by the publication of any successes from the few intentional introductions covered in this paper.     

Use of Dactylopius coccus Costa (Hemiptera: Coccoidea) Pigments in the Detection of Larvae and Pupae of Plutella xylostella (L.) (Lepidoptera: Yponomeutidae)

Carmines obtained from the dye of Dactylopius coccus Costa (Hemiptera: Coccoidea) were used for the detection of larvae and pupae of Plutella xylostella (L.) (Lepidoptera: Yponomeutidae) in broccoli inflorescences. Larvae were dyed with carmine II and red cochineal, while the majority of the dyes, with the exception of carmine III and the aqueous extract, were suitable to dye pupae. In the broccoli lumps exposed to the dyes, only the verge of the stems were actually dyed, right in the position where the incision took place, an appropriate characteristic for implementing this technique for commercial use.     

First study of the biology of Cryptolaemus montrouzieri and its potential to feed on the mealybug Dactylopius opuntiae (Hemiptera: Dactylopiidae) under laboratory conditions in Morocco

Abstract

Dactylopius opuntiae, is known as specific Opuntia cochineal in many countries around the world. This sap-sucking insect was first detected in Morocco in 2014. To address the problem, the feeding potential of different development stages of Cryptolaemus montrouzieri Mulsant, a biological control agent against mealybugs, was investigated on different development stages of D. opuntiae. Fourth instar larvae and adults of C. montrouzieri were the most voracious feeders on different instars of the mealybug. The numbers of mealybug eggs consumed by first, second, third and fourth instar larva and adults of C. montrouzieri were 36.18?±?1.84, 68.08?±?4.17, 280.55?±?5.41, 540.55?±?5.35, 6514.13?±?64.28, respectively. The numbers of mealybug nymphs consumed by the same stages of C. montrouzieri were 35.43?±?1.75, 67.73?±?3.88, 279.85?±?5.58, 539.63?±?5.08 and 6501.7?±?81.94 (first instars) and 34.83?±?1.20, 57.45?±?1.22, 83.80?±?1.92, 213.65?±?3.46 and 6013.23?±?35.46 (second instars), respectively. The corresponding figures for adult female mealybugs were 1.40?±?0.78, 10.65?±?1.83, 18.58?±?1.24, 25.23?±?1.10 and 197.15?±?3.29, respectively. The egg, larval, prepupal, pupal and adult stages occupied 3.36–3.69, 20.21–27.59, 1.31–1.59, 10.62–10.72 and 96.10–102.51?days, respectively when the coccinellid was reared on different stages of D. opuntiae. The results indicate that C. montrouzieri has the potential to be used as a biocontrol agent in Morocco.     

The Opuntia (Cactaceae) and Dactylopius (Hemiptera: Dactylopiidae) in Mexico: a historical perspective of use, interaction and distribution

A historical perspective on the use and production of species of Dactylopius (Hemipetera: Dactylopiidae) and Opuntia (Cactaceae: Opuntioidae), information on their origin, diversity and distribution in Mexico are reviewed, and aspects of their conservation are discussed. The use and exploitation of both genera are part of Mexican cultures since prehistory. Opuntia species were among the main components of human diet during pre-agricultural times. Cochineal was used and probably cultivated at least from the Tenth century. During the colonial period, cochineal generated significant benefits to the Spaniard colonizers and Mexico was the world’s first producer of insects and dyes until the mid Nineteenth century. Currently, Mexico is the main producer of Opuntia cladodes and prickly pear, but cochineal cultivation is marginal and only maintained in traditional indigenous systems. Mexico is one of the main areas of diversity of Opuntia, having 83–104 out of nearly 200 species worldwide. More than 50 species are used mainly as food, fodder and medicine and 20 species are cultivated with different degrees of domestication. The genus Dactylopius includes nine species, with five of them naturally occurring in Mexico. Only D. coccus has been cultivated and domesticated but other wild species have been used throughout history. Arid and semiarid areas of Mexico are among the most important reservoirs of biological diversity for both genera, particularly for D. coccus. Specific measures for protection of such biodiversity and generic resources are required. Strategies for in situ conservation combined with re-established use and cochineal production may enhance conservation policies.     

Evaluation of three varieties ofOpuntia ficus-indica (L.) Miller as hosts of the Cochineal insectDactylopius coccus costa (Homoptera: Dactylopiidae) in a semiarid area of northeastern Mexico

Three varieties of prickly pearOpuntia ficus- indica (Villanueva, Copena, and Jalpa varieties) were evaluated in their capacity to be host of the cochineal insect (Dactylopius coccus Costa) in two localities of northeastern Mexico. The experiment was carried out for two seasons, winter and summer, in 1998. Variables under evaluation were: fresh weight of grana, dry weight of grana, and number of insects. The Villanueva variety showed the highest production for the three variables and there were no differences between the other two varieties. Iturbide locality was superior to Linares for the three variables. Higher production (both dry and fresh weight of grana) was obtained during winter and there were no differences between seasons for number of insects. Figures obtained for the Villanueva variety are slightly higher than those reported in literature for the most productive cochineal areas in Mexico.     

胭脂虫寄生对仙人掌生长的影响

从印榕仙人掌(Opuntia ficus-indica Mill)植株高度、新增茎片数量和新增茎片面积3个方面研究不同密度胭脂虫Dactylopius coccus Costa寄生对仙人掌生长量的影响。结果表明:1)胭脂虫寄生对寄主仙人掌有明显的抑制作用,未被寄生的仙人掌株高、茎片数量和茎片面积的增加均明显大于被寄生的仙人掌;2)随着胭脂虫寄生密度的增加,仙人掌植株生长量的增加相应减少,生长高峰期的出现也会相应推迟;3)胭脂虫的寄生密度应控制在1000头/株以下,过大会导致仙人掌的死亡。     

Match and mismatch: Integrating consumptive effects of predators,prey traits,and habitat selection in colonizing aquatic insects

Predators are a particularly critical component of habitat quality, as they affect survival, morphology, behavior, population size, and community structure through both consumptive and non‐consumptive effects. Non‐consumptive effects can often exceed consumptive effects, but their relative importance is undetermined in many systems. Our objective was to determine the consumptive and non‐consumptive effects of a predaceous aquatic insect, Notonecta irrorata, on colonizing aquatic beetles. We tested how N. irrorata affected survival and habitat selection of colonizing aquatic beetles, how beetle traits contributed to their vulnerability to predation by N. irrorata, and how combined consumptive and non‐consumptive effects affected populations and community structure. Predation vulnerabilities ranged from 0% to 95% mortality, with size, swimming, and exoskeleton traits generating species‐specific vulnerabilities. Habitat selection ranged from predator avoidance to preferentially colonizing predator patches. Attraction of Dytiscidae to N. irrorata may be a natural ecological trap given similar cues produced by these taxa. Hence, species‐specific habitat selection by prey can be either predator‐avoidance responses that reduce consumptive effects, or responses that magnify predator effects. Notonecta irrorata had both strong consumptive and non‐consumptive effects on populations and communities, while combined effects predicted even more distinct communities and populations across patches with or without predators. Our results illustrate that an aquatic invertebrate predator can have functionally unique consumptive effects on prey, attracting and repelling prey, while prey have functionally unique responses to predators. Determining species‐specific consumptive and non‐consumptive effects is important to understand patterns of species diversity across landscapes.     

不同培育模式胭脂虫产量评估

对云南禄丰两种培育模式下胭脂虫Dactylopius coccus Costa产量进行了调查与评估,结果表明:1)在大棚内培育近3年的梨果仙人掌植株上接种培育胭脂虫,每年每667 m2大棚约可产胭脂虫干虫32kg;2)在大棚内悬挂仙人掌茎片上接种培育胭脂虫,每667 m2仙人掌寄主林每年所产茎片约可产胭脂虫干虫9 kg。     

Resource dependence in a new ecosystem: A host plant and its colonizing community

The introduced black locust (Robinia pseudoacacia) has become an invasive plant species in Europe. The introduction of alien plants such as the black locust may modify ecosystem composition and functioning. In response to the presence of a potential host plant, herbivores can adapt and shift to the consumption of the new host plant. In Eastern-Central Europe, the seed predator Bruchophagus robiniae (Hymenoptera: Eurytomidae) is an important consumer of black locust seeds which presumably shifted from its formerly host species to black locust. We tested the influence of host plant abundance on a seed predator – parasitoid community. We found that the seed predator B. robiniae was present in higher numbers in woodlots than in small patches of black locust. The density of the specialist parasitoid Mesopolobus sp. was lower in woodlots than in small patches, while the generalist parasitoid Eupelmus urozonos was evenly distributed between woodlots and small patches of black locust. We found that parasitoid species are influenced by the patch size of host plants, thus characteristics of introduced host plants can also manifest in higher trophic levels.     

The effect of microhabitat feeding site selection on aphid foraging and predation risk

Organisms attempt to optimize foraging by maximizing resource acquisition while minimizing predation risk. Aphids (group-living, phloem-feeding insects) routinely change feeding positions and interact with predators and parasites at the single-leaf scale. Here, we assess the life history and predation risk consequences of within-leaf feeding site choices in pea aphids in response to different natural enemies. First, three-chambered clip cages were used to isolate first instar aphids anterior and posterior to a centrally feeding adult on the underside of a single broad bean leaf. Development time to adulthood did not differ between feeding sites, nor did fecundity within the first 24 h of reproduction. Second, we recorded the frequency and latency of natural enemy attacks on aphids adhered to three leaf sites, matching those of the clip cage experiment, on the underside of a single leaf. Aphids feeding nearest the leaf petiole were at greatest risk of predation by a foliar foraging coccinellid predator, Hippodamia convergens, but not by a parasitoid wasp, Aphidius ervi. Thus, feeding nearer the leaf petiole provided no individual life history benefits and exposes the aphid to increased predation risk. We further discuss the notion that feeding at these sites may provide inclusive fitness benefits for colony mates via alarm signaling and subsequent decreased predation success.     

The effects of host age and superparasitism by the parasitoid, Microplitis rufiventris on the cellular and humoral immune response of Spodoptera littoralis larvae

To study the dynamics of stage-dependent immune responses in Spodoptera littoralis (Boisd.) larvae (Lepidoptera: Noctuidae), single and superparasitism experiments were carried out using the parasitoid Microplitis rufiventris Kok. (Braconidae: Hymenoptera). Compared to younger (preferred) host larvae, the older (non-preferred) host larvae displayed a vigorous humoral response that often damaged and destroyed the single wasp egg or larva. Superparasitism and host age altered both the cellular and humoral immune responses. Younger host larvae showed a stronger encapsulation response compared to older host larvae. Moreover encapsulation rates in younger hosts (e.g., second instar) decreased with increasing numbers of parasitoid eggs deposited/larvae. In older larvae, the encapsulation rate was low in fourth, less in fifth and absent in sixth instar hosts. Conversely, the order and magnitude of the cellular immune response in S. littoralis hosts were highest in second instar larvae with the first instar larvae being a little lower. The immune response steadily decreased from the third through to the fifth instar and was least obvious in the sixth instar. In contrast, the general humoral immune response was most pronounced in sixth instar larvae and diminished towards younger stages. The results suggest that both cellular and humoral responses are stage-dependent. Wasp offspring in younger superparasitized host larvae fought for host supremacy with only one wasp surviving, while supernumerary wasp larvae generally survived in older superparasitized larvae, but were unable to complete development. Older instars seem to have a method for immobilizing/killing wasp larvae that is not operating in the younger instars.     

Community science data suggests that urbanization and forest habitat loss threaten aphidophagous native lady beetles

1. Community scientists have illustrated rapid declines of several aphidophagous lady beetle (Coccinellidae) species. These declines coincide with the establishment of alien coccinellids. We established the Buckeye Lady Beetle Blitz program to measure the seasonal occupancy of coccinellids within gardens across a wide range of landscape contexts. Following the Habitat Compression Hypothesis, we predicted that gardens within agricultural landscapes would be alien‐dominated, whereas captures of natives would be higher within landscapes encompassing a high concentration of natural habitat.
2. Within the state of Ohio, USA, community scientists collected lady beetles for a 7‐day period across 4 years in June and August using yellow sticky card traps. All identifications were verified by professional scientists and beetles were classified by three traits: status (alien or native), mean body length, and primary diet. We compared the relative abundance and diversity of coccinellids seasonally and determined if the distribution of beetles by size, status, and diet was related to landscape features.
3. Alien species dominated the aphidophagous fauna. Native aphidophagous coccinellid abundance was positively correlated with forest habitat while alien species were more common when gardens were embedded within agricultural landscapes. Urbanization was negatively associated with both aphidophagous alien and native coccinellids.
4. Synthesis and Applications: Our census of native coccinellid species within residential gardens—a widespread and understudied habitat—was enabled by volunteers. These data will serve as an important baseline to track future changes within coccinellid communities within this region. We found that native coccinellid species richness and native aphidophagous coccinellid abundance in gardens were positively associated with forest habitat at a landscape scale of 2 km. However, our understanding of when and why (overwintering, summer foraging, or both) forest habitats are important remains unclear. Our findings highlight the need to understand how declining aphidophagous native species utilize forest habitats as a conservation priority.

     

Patch residence decisions made by Aphidius colemani in the presence of a facultative predator

One of the key questions in ecology is how animals optimally allocate their time in an environment with patchily distributed resources and competing organisms. Here we investigate the effects that an aphid predator, Macrolophus caliginosus (Wagner) (Hemiptera: Miridae), has on the searching behavior and the patch residence decisions of an aphid parasitoid, Aphidius colemani (Viereck) (Hymenoptera: Aphidiidae). A computer programme was designed that allowed the recording and saving of direct observations. The time allocated to different activities by a female parasitoid wasp in the presence or absence of the predator M. caliginosus was investigated. The experiments were conducted under controlled environment conditions using leaves of sweet pepper, Capsicum annuum L. (Solanaceae) and Myzus persicae (Sulzer) (Hemiptera: Aphididae) as the host plant–prey species system. The parasitoid spent significantly less time on ‘secondary’ activities, such as preening and resting, when the predator was present. Survival analysis showed that the parasitoid had a higher patch-leaving tendency when the predator was present.     

Dose-dependent influence of Microplitis rufiventris factors on developmental rate and growth of last-instar Spodoptera littoralis larvae

The solitary endoparasitoid, Microplitis rufiventris, attacks and can develop in earlier instars of Spodoptera littoralis larvae with preference to third‐instar larvae. We used the last stadium (sixth instar), a stage which is not naturally parasitized. The newly moulted larvae (0–3 h old) of this stadium were more acceptable for parasitization by the wasp females than the older ones (24 h old). Parasitization by M. rufiventris wasp of last instar S. littoralis larvae leads to dose (no. of eggs + parasitoid factors)‐dependent effects which were more pronounced at 20°C than at 27°C. A single oviposition into a sixth instar host larva resulted in normal development of the host. However, superparasitization increased the proportions of developmentally arrested hosts and number of live wasp larvae. Development of supernumerary individuals of the parasitoid in the host larva leads to dose‐related adverse effects on host growth and development. The present study may provide interesting opportunities for studying the physiological bases of host–parasitoid interactions and parasitoid intra‐specific competition in the biological system considered.     

Characterization of fulgorid waxes (Homoptera:Fulgoridae:Insecta)

A series of waxes produced by three fulgorid species are shown to be mixtures of homologs indentical to those previously found in the unrelated cochineal insect Dactylopius confusus. Using direct insertion probe mass spectrometry, the intact wax was found to give characteristic spectra obviating the need for extensive hydrolysis. The utility of these compounds as taxonomic characters in Fulgoridae is discussed.