Kermes echinatus

Porcelli, Francesco & Pellizzari, Giuseppina, 2014, Description of female nymphal instars and adult female of Kermes echinatus Balachowsky (Hemiptera, Coccoidea, Kermesidae) based on specimens from Crete and mainland Greece, with a discussion on geographical variation, Zootaxa 3878 (1), pp. 61-74 : 65-71

Comments on K. echinatus , K. vermilio and K. hermonensis .

As previously reported K. echinatus , K. vermilio and K. hermonensis share several morphological characters (table 1).

Comparative morphology of adult females. Adult female K. echinatus and K. vermili o have neither segmented legs, nor vestigial tubercles. Adult females of K. hermonensis and other described Palearctic and Nearctic Kermes species have segmented legs, even if somewhat reduced ( Leonardi, 1920; Balachowsky, 1950; Borchsenius, 1960; Bullington & Kosztarab, 1985; Liu, 1995; Liu & Shi, 1995; Spodek et al., 2012; Spodek & Ben-Dov, 2014).

The adult females of K. echinatus and K. vermilio are clearly separable on the basis of several morphological characters ( Table 1 ). In K. vermilio , the number of marginal spine-like setae increases from 1st -instar (58–72) to adult female (146–266), whereas in K. echinatus , the number of marginal spine-like setae is markedly lower than in K. vermilio and remains about the same in all instars (52–68). The reduction in the number of antennal segments in K. echinatus and K. vermilio is attained in two different ways, taking into account that the first-instar nymphs have 6-segmented antennae. In K. vermili o, the second-instar female has 5-segmented antennae, the third-instar female has 2- or 3-segmented antennae, whereas the adult female has monomerous antennae, each at least 2 times longer than wide. The reduction in the number of segments therefore occurs in a progressive way. However, in K. echinatus , the second-instar female has 1–3-segmented antennae whereas both the third-instar female and adult female have short, tubercle-like antennae. Here, the reduction in the number of segments occurs abruptly between the first- and second-instar females. With regard to the legs, those of the third-instar K. vermili o are tubercle-like whereas only the anterior legs are reduced to a tubercle in the third-instar K. echinatus ; all other legs are absent or indistinct.

In K. hermonensis , the number of marginal spine-like setae varies slightly among the different instars, attaining a maximum of 74–80 spines in the third-instar; antennae are 6 segmented in all the instars even if the segmentation is indistinct in some specimens; legs are 3 segmented starting from second-instar female onwards (Spodek & Ben- Dov, 2014).

Marotta & Tranfaglia (2001) first reported and described a pair of frontal lobes near the antennae in second- and third-instar females, second-instar male and prepupa of K. vermilio . Frontal lobes were also observed by us in the corresponding K. echinatus instars but were noted only in second-instar males of K. echinatus by Spodek & Ben-Dov (2014). According to the same authors, frontal lobes are present also in K. hermonensis second-instar male. As reported by Marotta & Tranfaglia (2001), the frontal lobes are much more recognizable in newly-moulted specimens and under phase contrast.

Host plants and distribution. Both K. echinatus and K. vermilio live on evergreen oaks: K. echinatus was collected in Israel on Q. calliprinos (Spodek & Ben-Dov, 2012; 2014), whilst in continental Greece, it was collected on Q. ilex ( Stathas et al., 2013) and in Crete off Q. coccifera by us. K. echinatus was previously only known from Israel but these recent records from Athens and Kalamata on mainland Greece ( Stathas et al., 2013) and from Aradena (Crete) extend the known distribution suggesting that it could be distributed over the same geographical areas as its host plants.

K. vermilio has been recorded on Quercus rotundifolia (= Q. ballota ), Q. coccifera , Q. ilex , and Q. suber ; it is widely distributed in Mediterranean countries (Ben-Dov et al., 2014).

K. hermonensis , just described in Israel off Q. look and Q. ithaburensis by Spodek and Ben-Dov (2014), has now been recorded in Turkey off Q. infectoria (Bora et al., 2014) .

PLATE 1. Kermes echinatus Balachowsky a) In vivo just moulted third-instar female nymph on twig of Quercus coccifera L., Aradena, Crete, April 7, 2010; b) crawler, slide mounted whole body in latero-ventral view; c) crawler, marginal spines of metathorax and part of abdomen, to show the two rows of larger (white arrow) and smaller (black arrow) spines; d) occipital and lateral ventral view of a crawler body margin to show spines; e) second-instar female nymph, side view; black arrows point to dorsum; f) right-side view of second-instar female nymph to show frontal lobe length (black arrow) in comparison with the length of antenna (white arrow); g) frontal lobe of second-instar female nymph, from venter.

PLATE 2. Kermes echinatus Balachowsky h) third-instar female nymph, dorso-ventrally slide-mounted whole body; i, j, k) abdominal margin respectively of second- and third-instar female nymph and adult female, dorso-ventrally slide-mounted. Excess dorsal cuticle borders the body margin marked by marginal spines (white arrows); l) adult female thorax margin; m) adult female ventral bi-trilocular pores (black arrows); n) adult female, abdominal ventral multilocular pores; o, p, q) adult female tubular ducts; r) adult female, dorso-ventrally slide-mounted whole body; s) adult female antenna.