Ranjith A P, Quicke Donald L J, Saleem U K A, Butcher Buntika A, Zaldívar-Riverón Alejandro, Nasser M
Insect Ecology and Ethology Laboratory, Department of Zoology, University of Calicut, Kerala, Pin: 673635, India.
Department of Zoology, Malabar Christian College, Calicut, Kerala, Pin: 673001, India.
PLoS One. 2016 Jun 29;11(6):e0156997. doi: 10.1371/journal.pone.0156997. eCollection 2016.
The vast majority of braconid wasps are parasitoids of other insects. Although a few cases of pure phytophagy (primary gall production and seed predation) are known, no previous entomophytophagous species (i.e. ones that display entomophagy and phytophagy sequentially), has been discovered among braconids. We describe the detailed biology and specialized larval morphology for the first confirmed entomophytophagous braconid species. Leaf galls on Garuga pinnata Roxb. (Burseraceae) in India, induced by the psyllid, Phacopteron lentiginosum Buckton (Hemiptera: Psylloidea, Phacopteronidae) were sampled throughout a period of several months and found to suffer a high level of attack by a new species Bracon garugaphagae Ranjith & Quicke which is here described and illustrated. The wasps oviposit singly into the galls without paralysing the psyllids. The larvae first attack psyllid nymphs which they seek out within the gall, kill them with a single bite and consume them. Unique dorsal abdominal tubercles, with eversible tips present on the abdominal segments of the larvae that are used to help maintain larval position while feeding, are illustrated. After consuming all available prey, the larvae continue feeding on gall tissue until mature enough to spin cocoons and pupate. The new species illustrates, for the first time, a possible intermediate stage in the evolution of pure phytophagy within the Braconidae. Interestingly, the two unrelated seed predator Bracon species are also associated with Burseraceae, perhaps indicating that this plant family is particularly suited as a food for braconine wasps.
绝大多数茧蜂是其他昆虫的寄生蜂。虽然已知有少数纯植食性的案例(即形成虫瘿和捕食种子),但此前在茧蜂中尚未发现过食虫兼植食性的物种(即依次表现出食虫性和植食性的物种)。我们描述了首个经确认的食虫兼植食性茧蜂物种的详细生物学特性和特殊的幼虫形态。在印度,由木虱Phacopteron lentiginosum Buckton(半翅目:木虱总科,木虱科)诱导在羽叶嘉榄Garuga pinnata Roxb.(橄榄科)上形成的叶瘿,在几个月的时间里被采样,发现遭受了一种新物种——嘉榄食茧蜂Bracon garugaphagae Ranjith & Quicke的大量攻击,本文对该物种进行了描述和图示。这些茧蜂单独将卵产入虫瘿中,并不麻痹木虱。幼虫首先攻击它们在虫瘿内找到的木虱若虫,一口将其咬死并取食。文中展示了幼虫腹部独特的背侧瘤,其腹部节段上有可外翻的尖端,在取食时用于帮助维持幼虫的位置。在消耗完所有可得猎物后,幼虫继续取食虫瘿组织,直到成熟到足以吐丝结茧并化蛹。这个新物种首次展示了茧蜂科内纯植食性进化过程中可能的中间阶段。有趣的是,另外两种不相关的捕食种子的茧蜂物种也与橄榄科植物有关,这或许表明这个植物科特别适合作为茧蜂的食物。