Rubus vestervicensis (Rosaceae) — its hybrid origin revealed by DNA fingerprinting

Kraft, T., Nybom, H. & Werlemark, G. 199.5. Rubus vestervicensis (Rosaceae) — its hybrid origin revealed by DNA fingerprinting. — Nord. 3. Bot. 1.5: 237–242. Copenhagen. ISSN 0107-055X.
The large number of species in Rubus subgenus Rubus are thought to have arisen, at least in part, through hybridiation between facultatively apomictic species. R. vestervicensis is known only from a small island off the Swedish east coast. It has been suggested that it is a hybrid between R. grabowskii and R. pedemontanus . We have compared these species with DNA fingerprinting and our results support the hybridization hypothesis. All bands found in the fingerprint of R. grabowskii and about half of the bands found in R. pedemontanus were present in R. vestervicensis , suggesting that the latter species was derived from fertilization of an unreduced R. grabowskii egg cell with R. pedemontanus pollen.     

Phylogeny of Rubus (rosaceae) based on nuclear ribosomal DNA internal transcribed spacer region sequences

We used nuclear ribosomal DNA internal transcribed spacer region (ITS 1 - 5.8S - ITS 2; ITS) sequences to generate the first phylogeny of Rubus based on a large, molecular data set. We sampled 57 taxa including 20 species of subgenus Rubus (blackberries), one to seven species from each of the remaining 11 subgenera, and the monotypic and closely related Dalibarda. In Rubus, ITS sequences are most informative among subgenera, and variability is low between closely related species. Parsimony analysis indicates that Rubus plus Dalibarda form a strongly supported clade, and D. repens may nest within Rubus. Of the subgenera with more than one species sampled, only subgenus Orobatus appears monophyletic. Three large clades are strongly supported: one contains all sampled species of nine of the 12 subgenera; another includes extreme Southern Hemisphere species of subgenera Comaropsis, Dalibarda, and Lampobatus; and a third clade consists of subgenus Rubus plus R. alpinus of subgenus Lampobatus. Rubus ursinus appears to be a hybrid between a close relative of R. macraei (subgenus Idaeobatus, raspberries) and an unidentified subgenus Rubus species. ITS sequences are generally consistent with biogeography and ploidy, but traditionally important morphological characters, such as stem armature and leaf type, appear to have limited phylogenetic value in Rubus.     

Redberry mite, Acalitus essigi (Hassan) (Acari: Eriophyidae), an additional biological control agent for Rubus species (blackberry) (Rosaceae) in Australia

Abstract  Acalitus essigi , the eriophyoid mite that causes red berry disease in Rubus species (Rosaceae), was collected from the fruits of three species of weedy blackberry, R. anglocandicans , R. laudatus and R. ulmifolius , in south-west Australia. This is the first record for this species in Western Australia and these plants appear to be new host records for A. essigi , which causes uneven ripening of fruit. Information on the mite is reviewed in the context of determining its potential as a biological control agent for Rubus species, especially those that are not susceptible to Phragmidium violaceum (Uredinales), the rust fungus being released against species of European blackberry in Australia. Published records also show that A. essigi will attack a wide range of Rubus species including species of North American origin that currently escape biological control in Australia. It may also be useful for preventing the spread of commercial varieties of Rubus (e.g. raspberry and loganberry) that have escaped to become weedy. However, the mite may have limited dispersal ability and thus require redistribution.     

Within‐generation dynamics of leatherjackets (Tipula paludosa Meig.)

Larvae of Tipula paludosa (leatherjackets) are pests of grassland and cereals, and important prey items for a range of farmland birds. Their population dynamics from year to year have been the subject of study, but within‐generation dynamics have received much less attention. The duration and occurrence of instars and size of the population is important to both pest management and bird conservation. Leatherjackets were collected monthly from four grass fields over five generations (October to September). Count data were analysed for sources of variability and used to estimate the timing and duration of instars and population changes over a single generation. Instar durations were correlated with temperature. From the first to third instars, sample counts were strongly influenced by the location of the site and the generation. Fourth instar larvae showed a similar decline in numbers across all sites and generations. The duration and timing of first to third instars was more variable than that of the fourth instar, but there was limited evidence that this was influenced by temperature. Only the durations of the third and fourth instars were correlated. The population decline from April to September coincided with the onset of the fourth instar. Our results show that the factors influencing leatherjacket numbers change over the life cycle, but by the fourth instar, these are biotically driven. The predictability of its numerical decline indicates defined windows for crop damage and availability as prey. The stability of its timing suggests that day length may synchronize the annual cycle. Fixed timing of the fourth instar will have important consequences for the timing of crop damage and the conservation of farmland birds as climate changes.     

Effects of the chitin synthesis inhibitor buprofezin on survival and development of immatures of Chrysoperla rufilabris (Neuroptera: Chrysopidae)

Effects of buprofezin (Applaud), a chitin synthesis inhibitor, on survival and development of eggs, three instars, and pupae of Chrysoperla rufilabris (Burmeister) were determined in the laboratory. Buprofezin at three tested concentrations (100, 500, and 1,000 mg [AI]/liter) did not affect the viability and development of eggs when the eggs were treated, or third instars and pupae when those stages were treated. Although the degree of effects by buprofezin on larvae varied with instar, buprofezin at the higher concentrations (500 and 1,000 mg [AI]/liter) reduced survival rates 17-47% and prolonged the overall development from first instars to adult emergence by 2 or 3 d when first instars were treated, indicating that the first instar is the most vulnerable stage. When second instars were treated, the survival of C. rufilabris from second instars to pupae was not significantly affected. However, the developmental time from second instar to adult emergence was longer in the treatments with the highest concentration (1,000 mg [AI]/liter) than that with the lowest concentration (100 mg [AI]/liter). The compatibility of buprofezin with natural enemies in integrated pest management programs is discussed.     

Determining the number of instars in potato tuber moth Phthorimaea operculella (Zeller) using density‐based DBSCAN clustering

The potato tuber moth (PTM), Phthorimaea operculella (Zeller), is an important pest of Solanaceae crops and especially devastating to potatoes. There is no significant difference in morphological characteristics of PTM from the first to third instar larvae; therefore, it is difficult to directly determine the number of instars of this pest based on morphology. In the present study, head capsule width and length and mandible width of 340 PTM individuals were measured. Density‐based spatial clustering of applications with noise (DBSCAN) clustering was used for instar grouping. The results of DBSCAN clustering were compared with those obtained using Gaussian mixture models and k‐means clustering; the results of the three clustering methods were verified using Brooks–Dyar rule, Crosby rule and linear regression model. The clusters obtained using the three methods were the same and comprised four PTM instars with three morphological characteristics. Moreover, the results of the three methods fit the Brooks–Dyar rule, Crosby rule, frequency analysis and logarithmic regression model well. Head capsule width was the best morphological characteristic for determining the number of instars of PTM, and this characteristic may be used for determining PTM instars in the field. These results show that the DBSCAN clustering method is a promising tool for the identification of insect instars.     

中国直腹长蝽族三种若虫记述(半翅目:长蝽科:地长蝽亚科)

本文对直腹长蝽族(半翅目：长蝽科：地长蝽亚科)的3个种的若虫进行了首次描述,即东方完缝长蝽Bryanellocoris orientalis Hidaka,长刺棘胸长蝽Primierus longispinus Zheng和短头细颈长蝽Vertomannus brevicollum Zheng,其中前二者为该属若虫的首次记述;本文还通过扫描电镜观察对东方完缝长蝽Bryanellocoris orientalis Hidaka身体背面分布的浅色圆点的细微结构进行了揭示。     

Egg–larval opiine parasitoids (Hym., Braconidae) of tephritid fruit fly pests do not attack the flowerhead-feeder Trupanea dubautiae (Dipt., Tephritidae)

Abstract:  We investigated the potential impact of three opiine tephritid fruit fly parasitoids: Fopius arisanus (Sonan), Fopius caudatus (Szépligeti) and Fopius ceratitivorus Wharton, on the non-target native Hawaiian tephritid, Trupanea dubautiae (Bryan), infesting flowerheads of the endemic Asteraceae shrub Dubautia raillardioides Hillebrand. The three species are the only known opiine fruit fly parasitoids that attack host eggs (but occasionally attack first instars). F. arisanus , which originated in southeast Asia, is now widely established in Hawaii and elsewhere in the world, while the other two are African species currently in quarantine in Hawaii. In the laboratory, field-collected flowerheads of D. raillardioides containing T. dubautiae eggs and first instar larvae were exposed to naïve female wasps of each of the three Fopius species in the absence (no-choice test) or presence (choice test) of papaya fruit infested with eggs of the Mediterranean fruit fly Ceratitis capitata (Wiedemann), the parasitoids' normal host. All three Fopius species visited the papaya fruit much more often than the flowerheads, and displayed normal ovipositional responses (probing and stinging) on the fruit in the choice test. None of the three parasitoid species showed ovipositional responses to flowerheads in either choice or no-choice tests. As a result, not a single T. dubautiae egg or larva was attacked by any of the three parasitoids, indicating that these parasitoids of pest tephritids are unable to recognize the microhabitats of flowerhead-feeding tephritids. The results suggest minimal risk of non-target impact in these biological control agents.     

Locomotion ability variation among instars of the bean bug, Riptortus pedestris (Fabricius) (Heteroptera: Alydidae) nymphs

The nymphal locomotion ability (walking distance) of the stenophagous bean bug Riptortus pedestris (Fabricius) was studied in each instar. We measured the walking distance using two systems. The walking distance in photophase was measured for 6 h using a tracking system with a charge coupled device (CCD) camera and computer software. The daily activity of nymphs was measured by an actograph system counting the number of infrared beam intercepts. The actograph data were converted to distance using a linear regression against the data of the tracking system. The longevity of nymphs without food was also studied to estimate the potential walking distance. Using both the tracking and actograph systems, it was determined that first instars walked less than the other instars (only 10.7 m within 6 h). The second to fifth instars could move 20-25 m within 6 h, and this distance did not differ among instar. This indicates that first instars seldom move after hatching in the field. The walking distance for 24 h varied and was greatest for the third instars (80.8 m). The potential longevity of nymphs was found to increase with instar age. Potential locomotion ability (walking distance for 24 hxpotential longevity) was high in the third to fifth instars (approximately 340 m). The potential locomotion ability for the second instars was relatively low compared with the elder instars (approximately 180 m). From these results, nymphs of R. pedestris seem to adapt by identifying feeding site locations after hatching and elder instars may be able to find a novel feeding site after the degradation of previous habitat.     

Efficacy of chitin synthesis inhibitors on nymphal German cockroaches (Dictyoptera: Blattellidae)

Second- and fifth-instar Blattella germanica (L.), fed the chitin synthesis inhibitors triflumuron, chlorfluazuron, hexafluron, and UC 84572 (structure not disclosed) were examined for mortality and developmental abnormalities. All compounds were active against B. germanica (L.), with lower diet concentrations being required to kill second instars compared with fifth instars. Chlorfluazuron was significantly more active against second and fifth instars (LC50 = 0.000191 and 0.000363% AI, respectively for the second and fifth instars). UC 84572 also killed nymphs at extremely low concentrations (LC50 = 0.000508 and 0.000754% AI, respectively, for second and fifth instars). LC50's for hexafluron and triflumuron against fifth instars were more than 1,000 times higher than that for chlorfluazuron. Sensitive periods of exposure were determined by comparing effects when four different age classes of fifth instars (1-, 4-, 7-, and 10-d old) fed on the compounds for 3 d. Triflumuron was most effective when ingested during the first three age classes and hexafluron was most effective during the last three age classes. Chlorfluazuron and UC 84572 were most effective when ingested during the second age class (days 4-6). Adults surviving exposure during the fifth instar were often deformed and weak; they died at a greater rate than the controls. However, most surviving adults were able to reproduce normally.     

Three new color patterns of nymphs of Arvelius albopunctatus (De Geer) (Hemiptera: Pentatomidae)

Arvelius albopunctatus (De Geer) is widely distributed in the Neotropical region, being an important pest of Solanaceae. Color variation of nymphs was described for this and other pentatomid species and their knowledge is essential for an early identification. From December 2005 to July 2006 nymphs and adults of A. albopunctatus were collected in forest fragments in Criciúma, I?ara, Maracajá and Araranguá (SC, Brazil). Known morphs of nymphs of both 4th and 5th instars were observed, as well as three new morphs, here described and named red morph (4th and 5th instars), green morph (4th and 5th instars) and orange morph (5th instar).     

Inter- and intra-specific differences in the number of larval instars in British populations of 24 species of stoneflies (Plecoptera)

1. Ontogenetic changes during the life cycle of aquatic insects are important not only in life‐history studies but also in evaluating food‐web structure. They require information on the growth and number of larval instars but such information is lacking for many species, including Plecoptera. Therefore, the chief objectives of the present study were to determine inter‐ and intra‐specific differences in the number of larval instars in British populations of 24 species of stoneflies, to test Dyar’s hypothesis that growth followed a geometric progression, and to synthesise this information with previously published values for four British species. 2. Larvae were reared at constant temperatures in the laboratory from eggs from 63 populations (one to six populations per species). First instars from each population were divided into three batches and each batch was reared at one of three constant temperatures. For each species, the rearing temperature and source population had no significant effect on the mean size of each larval instar. 3. The relationship between the geometric mean length of each instar and instar number was well described by an exponential equation (P < 0.001, r² > 0.9 for all species), thus supporting Dyar’s hypothesis. Only one species, Brachyptera risi, had the same number of instars for males and females (12–13). For the other 15 herbivorous species and the four smaller carnivorous ones, the number of instars was higher for females than males (range 11–16 for males, 12–17 for females). The larger size of the females was due to their additional instars, not a sex difference in growth rates. In contrast, there was a clear growth separation of the sexes after the 9th or 10th instar for the four largest carnivores. The number of larval instars was highest for these four species (range 16–19 for males, 18–23 for females), and females were much larger than males. 4. A multiple regression equation with data from the present and previous studies (n = 27) showed that variability in the mean length of the first instar and the maximum number of larval instars for each species accounted for 88% and 91% of the variability in the mean length of the final instar for males and females, respectively. 5. Values for Plecoptera in other countries were in general agreement with those in the present study, especially in the same families. Two old, but widely quoted, high values are doubtful. The present study and four previous ones provide a sound basis for ontogenetic studies on 28 species of Plecoptera and their role in aquatic ecosystems.     

The larva of Norfolius (Neuroptera: Nymphidae)

The three larval stages of the sole species of Norfolius Navás, N.howensis (Tillyard), are described and figured. Features of possible phylogenetic value are discussed in relation to other known nymphid larvae, and differences between instars are appraised for the first time in the family.     

A new stem-borer of the genus Bucculatrix (Lepidoptera: Bucculatricidae) from Japan, with description of the life history

A new species of bucculaticid moth, Bucculatrix hamaboella sp. nov. (Host plant: Hibiscus hamabo , Malvaceae) is described from Wakayama Prefecture, Japan. The feeding habit of the new species is unique in that: (i) the young larva is a leaf miner forming a long red linear mine but in the later instars the larva becomes a stem borer; (ii) later instar larvae undergo double molts within a cocoonet (molting cocoon); and (iii) penultimate and final instars appear on the surface of the leaf as non-feeding stages. The external non-feeding larvae of B. hamaboella undergoing double molts within one cocoonet are considered to be an abbreviated form of the external feeding instars of other bucculatricids typically making first and second cocoonets, undergoing a single molt within each cocoonet. On the basis of morphological characters, this species is related to the species of Sections I and II (Host: Asteraceae) of Braun (1963), rather than to the species of Section VIII (Host: Malvaceae).     

Orientation Behavior,Development and Survival of <Emphasis Type="Italic">Trichoplusia ni</Emphasis> (Lepidoptera: Noctuidae) Larvae on Cotton Expressing Cry1Ac and Cry2Ab and Conventional Cotton

This study was conducted to determine the effects of Bt cotton leaves (Bollgard II), non-Bt cotton leaves, and a mixture of Bt+non-Bt cotton leaves on larval orientation behavior, survival and development of Trichoplusia ni in the laboratory. Results indicate that in a no-choice test, more first and fifth instars remained on Bt leaves than the third instars. All larvae that remained on the leaves gradually moved to leaf edge. In the choice between a Bt and a non-Bt leaf, more first instars moved to non-Bt leaves, whereas the third and fifth instars did not show significant difference in the first 8 h, but eventually more moved to non-Bt leaves. More first instars fed non-Bt leaves than third instars and fifth instars. When larvae fed Bt leaves, 100% of first instars, 92.7% of third instars and 51.1% of fifth instars died in 108 h. Once larvae pupated, >90% developed to adults. First and third instars that fed Bt leaves developed slower but their pupae developed faster than those on Bt+non-Bt leaves, whereas fifth instars developed similar on the three types of leaves. First and third instars that fed Bt+non-Bt leaves resulted in less heavy pupae than those fed non-Bt leaves; whereas the fifth instars that survived on Bt leaves produced lighter pupae.     

Pollen morphology of some selected plant species from Horton Plains,Sri Lanka

The pollen morphology of four species: Gaultheria leschenaultii (Ericaceae), Psychotria zeylanica (Rubiaceae), Rubus leucocarpus (Rosaceae) and Symplocos bractealis (Symplocaceae) from Horton Plains, Sri Lanka was investigated using LM and SEM. Psychotria zeylanica is endemic to Sri Lanka and the other three taxa are common in Horton Plains. Gaultheria leschenaultii has tetrads with 3-colporate, coarsely granular to granulo-rugulate pollen grains; in the polar region and at the colpus margin the exine is smooth with micro-rugulate structure. Psychotria zeylanica has 3- (or 4-) colporate, reticulate-spinulose to granular pollen grains. Rubus leucocarpus has 3-colporate, striate-perforate pollen grains and Symplocos bractealis has 3- (or 4-) colporate pollen grains with a verrucate-perforate exine. Pollen grains of these four species are very indicative of human impact and palaeoclimate.     

Dropping behaviour of larvae of aphidophagous ladybirds and its effects on incidence of intraguild predation: interactions between the intraguild prey, Adalia bipunctata (L.) and Coccinella septempunctata (L.), and the intraguild predator, Harmonia axyridis Pallas

Abstract.  1. Two experiments were performed in the laboratory to assess the behaviour of dropping from a host plant as a defence against intraguild predation in aphidophagous ladybird larvae.
2. In the first experiment, encounters were observed on bean plants between fourth instars of the intraguild predator species, Harmonia axyridis , and first instars of two other ladybird species, Adalia bipunctata (L.) and Coccinella septempunctata (L.). The percentages of first instars of the latter two species that dropped from the plant in response to attack differed dramatically, with 47.5% of C. septempunctata first instars dropping vs. 0% of A. bipunctata .
3. In the second experiment, first instars of A. bipunctata or C. septempunctata and a fourth instar of H. axyridis were allowed to forage together on bean plants for 3 h. During this time, 44.3% of C. septempunctata larvae dropped from the plant, but less than 2% of A. bipunctata larvae did so. In contrast, 95.0% of A. bipunctata larvae fell victim to intraguild predation by H. axyridis vs. only 54.5% of C. septempunctata larvae.
4. The significance of dropping behaviour of ladybird larvae as a defence against intraguild predation, and the relationship of dropping behaviour to species-specific habitat affinity of ladybirds, is discussed.