Duration of development and longevity inAphidius ervi andAphidius platensis [Hym.: Aphidiidae], two parasites ofMyzus persicae [Hom.: Aphididae]

Rate of development and longevity were studied inAphidius ervi Haliday andAphidius platensis Brèthes, two parasites of the green peach aphid,Myzus persicae Sulz. On paprika,A. ervi developed from egg to adult in 27.3 days (at 15°C) and 19.9 days (21°C),A. platensis in 19.9 days (15°C), 15.6 days (21°C) and 12.4 days (24°C). The period from oviposition to mummification was in both species roughly twice as long as the period from mummification to adult emergence. Males emerged slightly before females. Given water and honey,A. ervi lived 15.4 days (♂) and 13.1 days (♀) at 21°C. The effect of temperature on longevity was tested inA. platensis on this diet: at 15°C, 9.2 days (♂) and 7.9 days (♀); at 21°C, 12.0 days (♂) and 13.4 days (♀); and at 24°C, 7.4 days (♂) and 8.4 days (♀). When supplied only with water, both species lived for 1–3 days. When aphid-infested leaves were added, longevity increased by 3.5 days (A. platensis). The maximal longevity, obtained with water and honey, was somewhat reduced when leaves were added, probably due to mating and oviposition activities (A. ervi). Longevity was not significantly influenced by the different host plants during parasite development. Differences in longevity between the sexes were small and dependent on temperature and food.     

Effect of low temperature on emergence, fecundity, longevity and host-feeding by Trichogramma brassicae

The occurrence of sub-optimal temperatures during development of immature parasitoids can have important consequences on adult fitness. We investigated the impact of different regimes of low temperature on emergence, differential mortality, longevity and fecundity in Trichogramma brassicae Bezdenko (Hymenoptera: Trichogrammatidae). The host-feeding behaviour of adult females was also measured as an indicator of energy reserve at emergence. Acclimation of 30 days at 10 °C or 24 days at 13 °C allowed T. brassicae immatures to develop with a lower mortality than those exposed directly at 5 °C. Longevity and fecundity of females decreased at a lower rate with acclimation at 10 °C suggesting that acclimation at 13 °C may have depleted the energy reserves of individuals more than acclimation at 10 °C. Short photoperiod exposure during the maternal generation had no effect on progeny’s fitness. We found no difference among the treatments in females’ host-feeding behaviours, in differential mortality at emergence, in female’s mobility and in F1 sex ratio.     

Biological studies withChrysocharis parksi [Hym.: Eulophidae] a parasite ofLiriomyza spp. [Dipt.: Agromyzidae]

Biological studies withChrysocharis parksi Crawford, a parasite of agromyzid leafminers, were conducted.C. parksi successfully parasitized the following species in the genusLiriomyza Mik.,L. huidobrensis (Blanchard),L. sativae Blanchard,L. trifolii (Burgess), andL. trifoliearum Spencer. Successful parasite development was recorded from 8 plant families and 16 genera. Host plants which were suitable for leafminer development to the adult stage were also suitable for parasite development. Mean immature developmental period (egg to adult, usingL. trifolii as the host) at 21.1°, 26.7°, and 32.2° C was (for both sexes) 23, 14, and 14 days, respectively. Longevity of females provided only water was inversely related to temperature; significantly longer survival occurred at 21.1° C (5.0 days) compared to 26.7° C and 32.2° C (3.2 and 2.1 days, respectively). The addition of honey to the diet significantly improved longevity of both sexes at all temperatures. Adult female parasites which were provided an average of 33.0L. trifolii larvae per day produced an average of 135 offspring at a constant 26.7° C.C. parksi host-fed on ca. 3.7 leafminer larvae per day over an 11-day adult lifespan.      

Influence of different temperatures on the tachinid parastite,Sturmiopsis inferens [Dip.]

The influence of constant temperatures of 27, 29, 31 and 33°C and alternating temperature of 31/33°C (18/6 h) onSturmiopsis inferens Townsend was studied during 12 successive generations. The larval and pupal periods for male parasites were 13.5±0.5 and 11.0±0.3 days respectively and for female 12.8±0.5 and 11.1±0.3 days respectively in the 1st generatioin at 27°C. It decreased progressively with increase in temperature. Survival of females, fertility and fecundity were adversely affected at higher temperatures. A temperature range of 27–29°C appeared to be optimum for mass rearing of the parasite in the laboratory. The higher premature mortality observed at a constant 33°C was not observed at temperatures fluctuating between 31/33°C. Presumably under field conditions, where temperature is constantly fluctuating, the flies will be able to withstand a comparatively higher temperature.     

Development ofDiatraea Saccharalis [Lep.: Pyralidae] at constant temperatures

At constant temperatures between 15.6 and 32°C the incubation time of eggs ofDiatraea saccharalis (F.) was reduced by each increase in temperature. At 34°C the time decreased. Highest (98.6%) and lowest (9.9%) egg hatch occurred at 26 and 34°C, respectively. Larvae completed development at temperatures ranging from 22 to 34°C; however, only 4.4% of the larvae pupated at 34°C. Duration of the larval stage at 30°C (♂=18.1 days; ♀=19.1 days) was ca. 14 days shorter than at 22°C. Maximum rate of development in the pupal stage occurred at 28°C (ca. 6.8 days), and a higher temperature increased developmental time and mortality. Adult longevity and egg production generally were reduced with increasing temperatures and egg production was highest at 24°C (729.8 eggs/ moth). As many as 7 larval stages occurred; but most larvae completed development in 5 stages, and none completed development in less than 5 stages. The female larval stage was ca. 1 day longer than that of males, and this difference occurred primarily in the 5th stage.     

Effects of copulation temperature on female reproductive output and longevity in the wolf spider Pardosa astrigera (Araneae: Lycosidae)

The copulation duration of male wolf spider Pardosa astrigera, was significantly influenced by environmental temperature, as had been found in some insect species. Therefore, temperature during male courtship and copulation may influence the amount of sperm and seminal fluids transferred during copulation, which in turn could influence female fitness. In order to test this hypothesis, we subjected pairs of male and female P. astrigera to five temperature groups from 16 to 32 °C at an interval of 4 °C, and investigated whether and to what extent the various temperatures during male courtship and copulation influenced female reproductive output and female adult longevity under controlled laboratory conditions. With the increase of copulation temperature, females were more likely to lay egg sacs. The total egg sacs and lifetime fecundity of female were positively influenced by copulation temperature, whereas female lifetime spiderlings and adult longevity were independent of copulation temperature.     

Age-specific fecundity and life table of Trissolcus semistriatus, an egg parasitoid of the sunn pest Eurygaster integriceps

The effects of temperature on age‐specific fecundity and life table parameters of the egg parasitoid Trissolcus semistriatus (Nees, 1834) (Hymenoptera: Scelionidae) were examined under four constant temperature conditions (17, 20, 26 and 32°C), using eggs of the sunn pest Eurygaster integriceps Puton, 1881 (Hemiptera: Scutelleridae), an important pest of wheat, as hosts. The intrinsic rate of increase increased linearly, while the mean generation time and the doubling time decreased with increases in temperature. The net reproductive rate, however, varied without clear correlation with temperature. Fecundity tended to be higher at higher temperatures. The total number of eggs per female was estimated as 52.0 and 116.4 eggs, respectively, at 17°C and 32°C, with the highest fecundity rate during the first day of oviposition. The oviposition rate fluctuated from 4.4 to 14.3 eggs per day. Oviposition and postoviposition periods and longevity decreased when temperature increased. Maximum longevity for females was 21.6 days at 20°C, and female parasitoids lived longer than males at all temperatures. The development period ranged from 7.1 days (32°C) to 35.6 days (17°C) for males and from 8.4 days (32°C) to 37.2 days (17°C) for females. The development of female T. semistriatus required 166.7 degree‐days (DD) above a theoretical threshold of 11.8°C and the development of males required 142.9 DD above 13.1°C. The numbers of generations per year for female and male T. semistriatus, given the temperature in Tekirdag, Turkey, were estimated to be 9.0 and 8.8, respectively. The potential of the egg parasitoid for the control of E. integriceps is discussed.     

The progeny production of a hymenopterous parasitoid,Apanteles sp. groupultor,as affected by temperature

Adults of the parasiteApanteles sp. groupultor were held unter constant temperatures (15, 20, 26, 30°C) each within ±1°C. Total progeny production was significantly greater at 26°C, averaging 85 per female and decreased at 15°C and 30°C. Mating behavior showed that both sexes were a polygamous. The range of constant temperature did not greatly alter the progeny sex ratio when female parent had been mated. At 15°C, male activity was adversely affected when both sexes were exposed to it without previous mating, resulting in a higher number of male progeny. A temperature of 26°C was the most appropriate for normal sex ratio.      

Effect of temperature and host species on parasitism,development time and sex ratio of the egg parasitoid Trichogrammatoidea lutea Girault (Hymenoptera: Trichogrammatidae)

The developmental biology of Trichogrammatoidea lutea Girault (Hymenoptera: Trichogrammatidae) was studied at six constant temperatures (18, 21, 24, 27, 30 and 35 °C) on eggs of three lepidopteran host species: Helicoverpa armigera (Hübner) (Noctuidae), Chilo partellus (Swinhoe) (Crambidae) and Cadra cautella (Walker) (Pyralidae). T. lutea did not complete development at 35 °C on any of the three host species. Parasitism levels were highest on H. armigera at 27 °C (58%), C. cautella at 27 and 30 °C (31% and 28%) and C. partellus between 24 and 30 °C (13–17%). Realized progeny of T. lutea per parasitized host egg was influenced by host size. The number of progeny of T. lutea per parasitized host egg was highest on H. armigera, followed by C. partellus and lowest on C. cautella. The sex ratio was female biased on C. partellus, female biased on C. cautella with the exception of 21 °C and close to 1:1 on H. armigera. The rate of development from egg to pupa and egg to adult was fastest on H. armigera and slowest on C. partellus. Lower thresholds for development and degree days (DD) of T. lutea from egg to adult were 12.8 °C and 105.4 DD on H. armigera, 11.3 °C and 141.6 DD on C. partellus and 12.9 °C and 118.2 DD on C. cautella, respectively. Based on these results, H. armigera is the most suitable host for mass rearing of T. lutea for biological control of Lepidoptera pests because of the relatively high parasitism levels, short development time, greater clutch size and balanced sex ratio. C. cautella may also be used although longer exposure times might be required due to lower parasitism levels.     

A biological evaluation of five European cultures ofAnaphes flavipes [Hymenoptera: mymaridae], an egg parasite ofOulema melanopus [Coleoptera: chrysomelidae]

Comparative biological data on five European cultures ofAnaphes flavipes [Hymenoptera: Mymaridae], an egg parasite ofOulema melanopus [Coleoptera: Chrysomelidae], indicated differences in developmental rates as those individuals representing cultures from the southernmost latitudes developed the slowest at 21°C, while those from the northernmost latitudes developed the fastest at this temperature. At 15.6°C, however, the parasites from the southern latitudes developed faster than those from the northern latitudes. Variations in other biological attributes, including longevity and fecundity, were not statistically significant.     

Preimaginal development,adult longevity and fecundity ofEncarsia inaron (Hym.: Aphelinidae) parasitizingSiphoninus phillyreae (Hom.: Aleyrodidae) in California

A laboratory study of preimaginal development, adult longevity and fecundity ofEncarsia inaron (Walker) was conducted. Preimaginal developmental times varied with temperature, from 55–60 d at 15±1°C to 14–17 d at 30±1°C. No development took place at 10°C, which was approximately the developmental minimum estimated from regression analysis of developmental rates vs. temperature in the range 15–30°C. Development was slowed and survival was reduced at 32°C. Females lived an average of 18.6 days and laid a average of 159 eggs/female at 25°C. At 25°C, average preimaginal survival was 59.3%, and the sex ratio was 73.5% female. The net reproductive rate (R₀) forE. inaron calculated from these studies was 69.3, while the intrinsic rate of natural increase was 0.1686 individuals per individual per day. Oviposition was concentrated slightly in third instar nymphs of the host.     

Comparative biological studies on two species of predatory beetles of the genusCybocephalus [Col.: Cybocephalidae]

The development, reproduction and longevity ofCybocephalus micans Reitter andC. nigriceps nigriceps (Sahlberg) were studied under controlled laboratory conditions. The data obtained explain the distribution of the 2 predators in different climatic regions of Israel. Under constant temperatures ranging between 16° and 36° C, the duration of development of the egg. larva and pupa of the 2 species became shorter as the temperature increased. For each developmental stage, at each temperature tested, the mean duration of development ofC. n. nigriceps was higher than that ofC. micans. The average time needed for completion of a generation at 28° C was about 39 days forC. micans, as compared with 56 days forC. n. nigriceps. Progeny production of both cybocephalid species was higher and adult longevity was longer at 28° C than at 32° C.     

Effect of temperature on the development, fecundity, progeny sex ratio and life-table of Campoletis chlorideae, an endolarval parasitoid of the pod borer, Helicoverpa armigera

Development, survival, fecundity, progeny sex ratio (PSR) and age-specific life-table parameters of the parasitoid Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae) were examined at six different constant temperatures (12, 17, 22, 27, 32 and 37°C) in the laboratory [70 ± 10% RH and 10:14 h (light:dark) photoperiod]. Second instar larvae of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) were reared on chickpea (Cicer arietinum L.) and used as the host. Development times shortened as the temperature increased from 12 to 37°C. The estimated lower developmental threshold (tL) was 3.4°C. The thermal summation for total immature stages was 379.97 degree-days. A reciprocal relationship between temperature and longevity was observed in the range of 12–17°C. The maximum mortality of pupae (71.8%) occurred at 37°C. At 22°C, the yield of a female parasitoid averaged 137.3 ± 14.7 (mean ± SD) progeny, of which 89.6 ± 7.6 were daughters. The number of daughters produced decreased when the females were kept either above or below 22°C, although the PSR was female biased in the range of 17–27°C. The analyses of life-table parameters, developmental rates, reproduction, mortality and PSR suggest that maximum population growth (r _m ) is near 27°C. There was little variation observed in most of the desired qualities of C. chlorideae in the range of 17–27°C, and it appears that the parasitoid is adapted to a wide range of temperatures. We suggest that for maximum production the parasitoid should be reared at 22 ± 4°C and be released in areas where the temperature ranges between 17° and 27°C, as in the plains of northern India.     

Effects of cold storage on Thripobius javae (=T. semiluteus) (Hymenoptera: Eulophidae)

Thripobius javae (Girault) was introduced in 1995 from Israel into Italy to control the greenhouse thrips, Heliothrips haemorrhoidalis (Bouché). Following introduction, successive augmentative releases of this parasitoid gave unsatisfactory and contradictory results, mainly due to the difficulty in synchronising its availability in sufficient number at the time of release. Efficient storage of this biological control agent could improve its current production and use. The effects of different sets of storage techniques at a single temperature and with a combination of different temperatures and instars on several fitness traits (residual developmental time to adult emergence after the end of storage, pupal mortality, longevity with and without hosts and progeny of emerged adults) were evaluated in order to determine the best conditions for storing the parasitoid.

For the pupal stage, increasing storage up to 14 days, at 10°C, gave only a moderate reduction (33%) of a modified composite quality index of its fitness. In contrast, when adults were stored for more than 10 days, at 15°C, residual longevity and progeny were reduced significantly. A combination of two temperatures (10 and 15°C) for pupal storage and a combination of pupal (10°C) and adult (15°C) storage had detrimental effects on parasitoid fitness. Temperatures of storage lower than 15 and 10°C had detrimental effects on adults and pupae, respectively.     

A review of the history of research and control of <Emphasis Type="Italic">Rhipicephalus</Emphasis> (<Emphasis Type="Italic">Boophilus</Emphasis>) <Emphasis Type="Italic">microplus</Emphasis>, babesiosis and anaplasmosis in Uruguay

The effect of five constant temperatures (16, 20, 24, 28 and 32 °C) on the development, survival and reproduction of Tetranychus cinnabarinus (Boisduval) [=?Tetranychus urticae Koch (red form)] fed on cassava leaves was examined in the laboratory at 85% relative humidity. Development time of various immature stages decreased with increasing temperature, with total egg-to-adult development time varying from 27.7 to 6.7 days. The lower thermal threshold for development was 10.8 °C and the thermal constant from egg to adult was 142.4 degree-days. Pre- and post-oviposition period and female longevity all decreased as temperature increased. The longest oviposition period was observed at 20 °C with 20.4 days. Under different temperatures, mated females laid, on average, 1.0, 2.9, 4.7, 4.7 and 4.9 eggs per day, respectively. The maximum fecundity (81.5 eggs per female) was at 28 °C and the intrinsic rate of increase (r _m ) was highest (0.25) at 32 °C. The results of this study indicate that T. cinnabarinus population could increase rapidly when cassava leaves serve as a food source. At the appropriate temperature T. cinnabarinus could seriously threaten growth of cassava.     

Reproduction and population parameters of the Nearctic predator Geocoris punctipes at constant and varying temperature regimes

The heteropteran predator Geocoris punctipes (Say) has been used in augmentative biological control since 2000 to control Lepidoptera. However, surprisingly, few data are available about the influence of temperature on its population development, which is of key importance to plan the number and moment of releases to obtain sufficient pest reduction. The objective of this study was to evaluate daily and total fecundity, longevity and life table parameters (m_x, l_x, r_m, R, λ, T and TD) of G. punctipes at constant (16.8°C, 21.5°C, 24.5°C and 28.3°C) and corresponding varying (day/night) (21/11°C, 24/18°C, 27/21°C and 30/26°C) temperatures. Pairs of adult predators aged 24 h and originating from nymphs exposed to the same temperature regimes were kept at the above‐mentioned temperature regimes in Petri dishes containing Anagasta kuehniella (Zeller) eggs and an oviposition substrate. Tests were conducted in climatic chambers at the different temperature regimes and a RH 70 ± 10% and a 14L: 10D photoperiod. Reproduction, longevity and life table parameters were significantly affected by temperature, with clear differences between treatments at low (16.8°C, 21/11°C, 21.5°C, 24/18°C) or a high (24.5°C, 27/21°C, 28.3°C, 30/26°C) temperature regimes. Highest reproduction and fastest population growth of G. punctipes took place at average temperatures ranging from 24.5°C to 30°C, and neither reproduction nor population growth was negatively influenced by varying temperatures at any of the temperature regimes.     

Parasitism,longevity and progeny production of six indigenous Kenyan trichogrammatid egg parasitoids (Hymenoptera: Trichogrammatidae) at different temperature and relative humidity regimes

Six native Kenyan species/strains of Trichogramma and Trichogrammatoidea, recovered from Helicoverpa armigera were evaluated at six different temperatures (10, 15, 20, 25, 30 and 35°C) and two relative humidity levels (40–50 and 70–80%) with the aim of selecting strains adapted to warmer temperature regimes. The species/strains were collected from low (<700 m), medium (between 700 and 1200 m) and high altitude (>1200 m) locations and were evaluated for parasitism, adult longevity, progeny production and progeny sex ratio at the different environmental regimes. Eggs of the factitious host, Corcyra cephalonica Stainton (Lepidoptera: Pyralidae) were used in the investigations. Temperature and humidity interactions affected parasitism and progeny production. The highest parasitism at the two humidity levels was at 25 and 30°C for all the strains evaluated. Adult longevity was also significantly affected by the interaction of temperature and relative humidity and was longer at the lower than higher relative humidity. Survival followed a type I survivorship curve at lower temperatures and a type III survivorship curve at the higher temperatures. Trichogramma sp. nr. mwanzai from low altitude, Trichogramma sp. nr. mwanzai from medium altitude and Trichogrammatoidea sp. nr. lutea also from medium altitude lived longer than other strains at all the temperatures and relative humidity levels evaluated, including the warmest regimes of 30 and 35°C. These strains appear promising as candidates for augmentative biocontrol of H. armigera in Kenya.     

Temperature Effects on Survival and Development of Heleidomermis magnapapula in the Laboratory

The mermithid Heleidomermis magnapapula Poinar and Mullens, a parasite of the biting midge Culicoides variipennis (Coquillett), was exposed to constant temperatures in the laboratory. Survival of the free-living stages and development times of eggs and the parasitic phase were inversely related to temperature. Average preparasite longevity was 70, 46, 42, and 22 hours at 15.6, 21.1, 26.7, and 32.2 C, respectively. Females survived significantly longer than males. Longevity in days (females/males) at different temperatures was 17.3/11.0 at 4.4 C, 9.0/8.2 at 15.6 C, 5.9/5,1 at 21.1 C, 5.2/4.7 at 26.7 C, and 4.4/3.6 at 32.2 C. Embryogenesis required 44 ± 2 degree days above a thermal minimum of 10.1 C, while parasitic development in host larvae required 214 ± 10 degree days above a thermal minimum of 8.9 C. Parasite responses to temperature were very closely related to temperature-dependent host development patterns.     

The influence of storage temperature on spore viability of Mattesia trogodermae (Protozoa: Neogregarinida)

The viability of Mattesia trogodermae spores stored at different temperatures was assessed by the percentage infection induced in 30-day-old Trogoderma glabrum larvae. Exposure to 73°C and higher temperatures for 30 min was lethal to the spores. Spores stored at ?19°C survived better than those stored at 26.7°, 3.5°, or ?30°C.     

Effect of temperature on immature development and longevity of two introduced opiine parasitoids on Bactrocera invadens

Temperature‐dependent development, parasitism and longevity of the braconid parasitoids, Fopius arisanus Sonan and Diachasmimorpha longicaudata Ashmed on Bactorcera invadens Drew Tsuruta & White, was evaluated across five constant temperatures (15, 20, 25, 30 and 35°C). Developmental rate decreased linearly with increasing temperature for both the parasitoid species. Linear and Brière‐2 nonlinear models were used to determine the lower temperature threshold at which the developmental rate (1/D) approached zero. For F. arisanus, lower thresholds to complete development estimated with the linear and nonlinear models were 10.1 and 6.9°C, respectively. The total degree‐days (DD) required to complete the development estimated by the linear model for F. arisanus was 360. In D. longicaudata, the linear and nonlinear models estimated lower thresholds of 10.4 and 7.3°C, respectively, and the total DD estimated was 282. In F. arisanus, percentage parasitism differed significantly across all temperatures tested and was highest at 25°C (71.1 ± 2.5) and lowest at 15°C (46.4 ± 1.4). Parasitoid progeny sex ratio was female biased at all temperatures except at 20°C. In D. longicaudata, percentage parasitism was highest at 20°C (52.2 ± 4.0) and lowest at 15°C (27.7 ± 2.5). Parasitoid progeny sex ratio was female biased and similar for all temperatures. Adult longevity of both parasitoids was shortest at 35°C and longest at 15°C, and females lived significantly longer than males at all temperatures tested. Our findings provide some guidance for future mass rearing and field releases of the two parasitoids for the management of B. invadens in Africa.