Some biological factors affecting the production of the larval parasitoid Bracon brevicornis Wesm. (Hym., Braconidae)

Abstract

The number of progeny of Bracon brevicornis was greatly affected by the number of deposited eggs of Bracon females per host larva. The increase in the egg clutch size from 5 to 25 eggs/larva increases the progeny production. On the other hand, the increase in the egg clutch size of the parasitoid decreases the body size of produced female progeny. The ratios of parasitoid females‐host larvae and time of parasitization which leads to optimal parasitism were studied. The most appropriate crowding level of B. brevicornis females to O. nubilalis full grown larvae was studied. The sex ratio of produced parasitoid progeny was significantly affected by changing the sex ratio of parent parasitoids, while there was no effect on the number of deposited eggs per host.

Parasitism by Campoletis flavicincta on Spodoptera frugiperda in corn

“…Sex ratio of this parasitoid is around 0.5 in natural conditions, which is higher than that found in laboratory (Cruz et al, 1995), representing a problem at this parasitoid mass rearing. The cause of low sex ratio in C. flavicincta is unknown, but this event was also reported for other Hymenoptera parasitoids reared in the laboratory (Fuester et al, 1987;Zaki et al, 1994). Sex ratio of C. flavicincta may have been affected while its adults were in the laboratory, because parasitism occurred in an environment close to natural conditions -interior of field cage -where the sex ratio of C. flavicincta was very low (Table 1).…”

Responses of Lipolexis oregmae (Hymenoptera: Aphidiidae) to Different Instars of Toxoptera citricida (Homoptera: Aphididae)

“…However, T. diatraeae adults did not emerge from E. cyparissias pupae probably because of host defense mechanisms (Gross 1993;Pennacchio & Strand 2006). The number of T. diatraeae females (50) per E. cyparissias pupae may have been insufficient to generate the amount of toxins and immature individuals required to overcome the host defense mechanism (Zaki et al 1994;Andrade et al 2010). Encapsulated parasitoids were found inside dissected pupae of E. cyparissias.…”

Do parasitoid density and host age affect the parasitism of Palmistichus elaeisis (Hymenoptera: Eulophidae)?

“…The parasitoid density and age of the hosts pupae can affect parasitism capacity and reflect directly on parasitoid quality (THOMAZINI; BERTI FILHO, 2001;MATOS NETO et al, 2004), changing characteristics such as body size (BITTENCOURT; BERTI FILHO, 1999), longevity (SILVA-TORRES; MATTHEWS, 2003) and cycle length (BITTENCOURT et al, 2004). This shows the demand to improve the mass creation of parasitoids, aiming to know, especially, the ideal density and age in relation to the host to maximize their production (ZAKI et al, 1994;SAGARRA et al, 2000).…”