Reproduction of Ooencyrtus submetallicus (Hymenoptera: Encyrtidae) in egg densities of Euschistus heros (Hemiptera: Pentatomidae)

Knowledge about the ideal host ratio per female parasitoid reared in glass tubes is important for obtaining descendants with better biological quality. The study aimed to evaluate the reproduction of Ooencyrtus submetallicus (Hymenoptera: Encyrtidae) females in egg densities of Euschistus heros (Hemiptera: Pentatomidae) to find the most adequate relationship between parasitoids and hosts aiming at the parasitoid multiplication. The experiment was conducted with E. heros eggs at densities (parasitoid:host) of 1:3, 1:6, 1:9, 1:12, 1:15, or 1:18 with 24 hours of parasitism by O. submetallicus. The parasitoid females and the egg carton were placed in glass tubes and kept in a climate-controlled chamber. The percentage of parasitism was affected by the nonparasitised eggs. The emergence of adult parasitoids, number of parasitised eggs, number of individual parasitoids emerging per egg, the length of the parasitoids’ posterior tibiae, and the parasitoids’ longevity, life cycle, and sex ratio were not affected by the different densities of nonparasitised eggs subjected to treatments. Ooencyrtus submetallicus parasitised and developed in E. heros eggs in all evaluated densities, with 1:6 presenting the best combination of parasitoid and host.

Biology and Reproductive Behaviour of Apanteles taragamae Viereck (Hymenoptera: Braconidae), a Larval Parasitoid of Diaphania indica Saunders (Lepidoptera: Crambidae)

Apanteles taragamae (Hymenoptera: Braconidae) is a larval parasitoid of Diaphania indica (Saunders) (Lepidoptera: Crambidae), a minor pest of Cucurbitaceae crop. The aim of this study was to determine the behavior and biology of A. taragamae. The study was conducted under laboratory conditions by exposing 930 larvae of D. indica to be parasitized by 11 adult female parasitoid of A. taragamae (1 day old), which have been mated 24 hours prior to expose. Each female was exposed to 15 larvae/day until they died. The parameters used to measure the biology of A. taragamae were fecundity, longevity, and parasitism. Results showed that the longevity of adult females was 5.64 days, the parasitism was 96%, the number of egg laid was 76.40/day, the total number of eggs laid was 611.18, and potential fecundity was 752.73 egg.

A new substitute host and its effects on some biological properties ofOoencyrtus kuvanae

Lymantia dispar(L.) (Lepidoptera: Lymantriidae), commonly known as the gypsy moth, is a serious forest pest, and beneficial insects are particularly important for reducing its population numbers.Ooencyrtus kuvanae(Howard) (Hymenoptera: Encyrtidae) is an arrhenotokous, solitary egg parasitoid ofL. dispar. In this study, we evaluated a new substitute host,Philosamia ricini(Danovan) (Lepidoptera: Saturniidae) forO. kuvanae. We investigated some of the biological effects ofO. kuvanaeonP. ricinieggs. In this context, the importance of the age of the female parasitoid (1, 3 or 5 days old), host age (1–2 and 3–4 days old) and host number (40, 60 and 80 host eggs) were examined under laboratory conditions (25 ± 1 °C, 65 ± 5% relative humidity and a 16 : 8 h photoperiod [light : dark]). The highest rate of offspring production (89.90%) occurred with 40 (1–2-day-old) host eggs and 5-day-old females. The mean developmental period ranged from 16.5 ± 0.08 days to 18.7 ± 0.08 days. The mean lifespan of the parasitoid was 51.10 ± 1.1 (n= 60) days with bio-honey and 3.92 ± 0.14 (n= 60) days without food. The mean fecundity was 68.88 ± 3.22 offspring/female. Peak adult emergence occurred between 2 and 9 days. The mean oviposition and mean post-oviposition periods of the female parasitoid were 22.76 ± 1.37 days and 13.64 ± 1.40 days, respectively.O. kuvanaewas reared for more than ten generations on the eggs ofP. ricini. Based on our findings,P. ricinican be used to rearO. kuvanaefor the biological control ofL. dispar.

Nisbah kelamin dan pola peletakan telur parasitoid Trichogramma chilotraeae Nagaraja & Nagarkatti (Hymenoptera: Trichogrammatidae) pada berbagai jumlah inang

The objective of the research was to study sex ratio and oviposition sequence of egg parasitoid Trichogramma chilotraeae in relation with host density under laboratory condition. Parasitoid response with respect to oviposition sequence was examined by exposing five different host (egg) densities: 3, 6, 12, 24 and 48 on female parasitoids T. chilotraeae. Results showed that in general, female parasitoid laid its female progeny at the beginning of oviposition sequence. Host density was found to have a strong effect on sex ratio. Sex ratio increase with increasing of host number.

EFISIENSI PARASITISASI INANG SPODOPTERA LITURA (F.) OLEH ENDOPARASITOID SNELLENIUS MANILAE ASHMEAD DI LABORATORIUM

Eficiency of parasitization on larval host, Spodoptera litura (F.), by an endoparasitoid Snellenius (=Microplitis)manilae Ashmead in the laboratory. The armyworm, Spodoptera litura (F.) is the host of an endoparasitoid Snelleniusmanilae Ashmead. This research described the effect of host larval stage preference, the number of host exposure and theage of parasitoid on the resulting parasitization. Each group of the first to the fifth of host instar (30 larvae) was exposed for3 hours to a pair of four-day old parasitoids in a trial cage. The same exposures were conducted without choices by placingeach instar group within each trial cage. The parasitoid survival was observed by maintaining the parasitized larvae untiladult emergence. Each group of 10, 20, 30 and 40 of the second instar larvae were exposed for 12 hours/day to a matedfemale parasitoid. This experiment was conducted from the first day old parasitoid until the females died. The percentageof parasitization, superparasitization, oviposition and the fecundity of adults were recorded. Each group of thirty secondinstar larvae was exposed separately to a mated female parasitoid of 1 to 9 days old. The survival of progeny was recorded.All treatments in this observation were repeated 10 times. S. manilae preferred to lay eggs on the third (41.7%) followed bythe second (22.3%) instar larvae of S. litura. The lowest percentages of superparasitization obtained from the first and thesecond instar larvae were between 11 and 15% and the highest percentage of superparasitization obtained from the fourthinstar larvae was 52%. The highest survival of parasitoid was found on the exposure of the second instar larvae whichreached 16%. The highest efficiency of parasitism (80.9%) was found on the twenty of the second instar larval exposuredensity which produced 59% of optimal parasitization level, the average rate of egg laid by females was 25 eggs/day, andthe fecundity was 185 eggs/female. Female parasitoids of 1-7 days old gave the same opportunity to produce progenysurvival which was in the range of 10.3-25.7%.

PREFERENSI DAN TANGGAP FUNGSIONAL PARASITOID HEMIPTARSENUS VARICORNIS (GIRAULT) (HYMENOPTERA: EULOPHIDAE) PADA LARVA LALAT PENGOROK DAUN KENTANG

The preference and functional response of Parasitoid Hemiptarsenus varicornis (Girault) (Hymenoptera:Eulophidae) on host larvae of potato leafminers. The preference of Hemiptarsenus varicornis (Girault) on host larvae of potato leafminers (Liriomyza huidobrensis) and their functional response on host abundance were studied in laboratory. The preference test was conducted by releasing a female parasitoid in a cage containing two redbean leaves, one with 2nd instar and another one with 3rd instar. The functional response test was conducted by providing 3rd instar with density 1, 4, 6, 8, 10, and 13 larvae per leaf. The result showed that H. varicornis had the preference on 3rd instar larvae compared to 2nd instar, either for parasitisation or paralysis. Based on logistic regression analysis it was found that the parasitoid showed type II functional response on the increase of host abundance. The searching rate (a) and handling time (Th) for paralysis were 0.038 and 1.473 based on disk equation model, and 0.076 and 2.060 on ramdom equation model. For parasitisation activity, the value of a and Th were 0.012 and 4.649 based on disk equation model, and 0.014 and 5.075 on random equation model.