Developmental studies on Anagyrus mangicola (Hymenoptera: Encyrtidae), a parasitoid of the mealybug Rastrococcus invadens (Homoptera: Pseudococcidae)

Abstract

Anagyrus mangicola Noyes, a primary parasitoid of the mealybug Rastrococcus invadens Williams, a pest of fruit crops in West Africa, was studied under controlled conditions at 27°C and 75% r.h. Data are given on the larval stages, their morphology and duration of immature development. The sex ratios of emerging parasitoids, adult longevity, host stage preference, the relationship of the size of the emerging parasitoid to host stage and development time are also investigated.

Physiological and morphological development of Anagyrus ananatis at constant temperatures

“…The larvae gradually changed to hymenopteriform, but connection with the host skin through the stalk continued until the larva matured, which is typical of Encyrtiform larva (Clausen, 1940). The tremendous increase in body length of the second instar compared to the first instar was also reported for Anagyrus mangicola (Cross and Moore, 1992). The third instar grows more in width than length and ultimately changed orientation.…”

“…Developmental stages of A. ananatis were similar to Anagyrus mangicola Noyes (Cross and Moore, 1992). Encyrtiform eggs are characteristic of encyrtids.…”

“…The number of larval instars of encyrtids varies from two to five, with three being more commonly reported (Clausen, 1940). Three larval instars were reported for Anagyrus mangicola, (Cross and Moore, 1992) and four for Epidinocarsis lopezi De Santis (Odebiyi and Bokonon-Ganta, 1986;Lohr et al, 1989). Hypermetamorphosis (where two or more forms of larva are found during a developmental cycle), as observed in A. ananatis, is common among parasitic Hymenoptera, with the highest degree of variation in the first instar larvae following the successive molting (Clausen, 1940).…”

“…The third instar grows more in width than length and ultimately changed orientation. Reversing the orientation of mature larvae within the host body is common among encyrtids (Clausen, 1940;Cross and Moore, 1992). Although the parasitoid is a koinobiont, the host mealybug was killed within a few (6-8) days after parasitization.…”

Fecundity and survival of Anagyrus kamali (Hymenoptera: Encyrtidae) under different feeding and storage temperature conditions

“…For other Anagyrini species, like Anagyrus mangicola Noyes, the average survival of male and female parasi toids at 25 ± 2°C was shorter than A. kamali, with 16.7 ± 0.46 and 20.2 ± 0.30 days, respectively (Cross & Moore, 1992). Similar trends were observed for longevity of Anagyrus pseudococci (Girault) and Leptomastix abnormis (Girault) (Tingle & Copland, 1989), and also Ana gyrus dactylopii (Howard) (Mani & Thontadarya, 1988).…”