Effect of female size on host selection by a koinobiont insect parasitoid (Hymenoptera: Braconidae: Aphidiinae)

Abstract

Abstract. Body size is a main fitness component of insect parasitoids. We assessed the potential influence of maternal size of the parasitoid wasp Aphidius colemani Viereck (Hymenoptera: Braconidae: Aphidiinae) on its ability to parasitize the different instars of Aphis gossypii Glover (Hemiptera: Aphididae) on eggplant and cucumber. In the experiments "small" vs "large" parasitoid females were used. Females oviposited in all instars but more of the smaller hosts were parasitized. Host selection was affected by female size and the larger hosts were more frequently mummified by the large than the small females. Thus, parasitoid female size influenced host selection. This could affect the potential of the parasitoid to exploit populations of aphids that differ in their size structure. The importance of these results in terms of the ecological adaptations of the parasitoid and their implication for biological control are discussed.

Ecological Interactions Affecting the Efficacy of Aphidius colemani in Greenhouse Crops

“…As parasitoids alter their host-selection behavior in relation to their own body size, large and small parasitoids of the same species prefer larger and smaller aphids, respectively [ 144 , 146 ]. The inverse relationship between parasitoid size and handling time means that smaller aphid hosts are more often parasitized by smaller Aphidius individuals (because they have not yet developed effective defenses; [ 144 ]), while larger A. colemani have a wider range of accepted instars [ 44 , 45 ]. A strict preference for specific instars could affect the potential of the parasitoid to exploit aphid populations that differ in size structure.…”

Molecular and morphological characterization in Praon dorsale-yomenae species complex (Hymenoptera, Braconidae)

“…Taĉnije, ţenke parazitoida mogu menjati strategiju ovipozicije u zavisnosti od gustine populacije domaćina. Jako je bitno i parazitiranje domaćina u njegovom najranijem razvojnom stadijumu (I i II larveni stadijum, kada je najveća gustina populacije domaćina), tako da se parazitoid razvije pre nego što domaćin dostigne polnu zrelost i poĉne da produkujuje nove jedinke(Lykouressis et al 2009).Taksonomske studije podfamilije Aphidiinae doprinose korektnoj identifikaciji vrsta koje predstavljaju prirodne kontrolne agense vašiju, što moţe biti od kljuĉnog znaĉaja za uspehe bioloških kontrolnih programa. Poznavanje tritrofiĉkih asocijacija (vaš-parazitoid-biljka) sa odreĊenih prostora, odnosno populacioni diverzitet parazitoida, moţe biti od kljuĉnog znaĉaja za biokontrolne strategije.…”