The egg endoparasitoids of Macrolenes dentipes (Olivier) (Coleoptera: Chrysomelidae), with description of a new species of Aprostocetus Westwood and notes on its host (Hymenoptera: Eulophidae)
Author
Viggiani, Gennaro
Dipartimento di Agraria, Università degli Studi di Napoli “ Federico II ”, Laboratorio di Lotta biologica, Via Università, 133, Portici (NA), Italy
Author
Filella, Francesco
Istituto Professionale Agrario, Spezzano Albanese (CS), Italy - francescofilella @ gmail. com
francescofilella@gmail.com
Author
Bernardo, Umberto
CNR, Institute for Sustainable Plant Protection, SS of Portici, Portici (NA), Italy - umberto. bernardo @ ipsp. cnr. it
umberto.bernardo@ipsp.cnr.it
text
Fragmenta entomologica
2021
2021-03-15
53
1
57
64
journal article
56255
10.13133/2284-4880/483
a11ea050-c34d-47de-9366-75f0defdb9f0
2284-4880
8147988
9E0B0411-B21C-4C1D-8A95-054A951B09C5
Notes on
Macrolenes dentipes
The genus
Macrolenes
Chevrolat, 1836
, includes the species
Macrolenes dentipes
(Olivier, 1808)
and
Macrolenes bellieri
(Reiche, 1860)
; the latter recorded only in
Sicily
.
M. dentipes
is widely distributed in the Mediterranean region (
Regalin & Medvedev 2010
) and rather easily recognized for the male front legs having long and dentate femora (Fig. 14). The adults are observed on several plants [
Pistacia
,
Rhus
(Anacardiaceae)
,
Quercus
(Fagaceae)
,
Fraxinus
(Oleaceae)
,
Paliurus
and
Ziziphus
(Rhamnaceae)
] from May to August, but they are preferably active leaf-eater on
Pistacia lentiscus
L. (
Agoiz-Bustamante et al. 2019
). Adults of
M. dentipes
are phytophagous, while larval stages are phyto-zoo-saprophagous (
Schöller 1998
). The females oviposit eggs in clusters attached to the leaf surface by long strands. The first instar larva is undescribed. Larval development occurs on the soil. The third larva, described by Medvedev & Schöller (2002) on specimens collected under a stone covering an ant’s nest under a
Quercus ilex
tree, is protected by a simple case, light grey to brownish, with the fine line-like structure on the surface.
M. dentipes
is one of the ant-nest beetles (
Agrain et al. 2015
), but according to
Schöller & Witte (2007)
, the larvae of the most advanced genera of Clytrinae (
Labidostomis
and
Macrolenes
) have lost secondarily the ability to penetrate into the ant nests and remain at the entrance of the host’s nest, namely, a species of
Tapinoma
: a new, protected and food-rich niche of a dolichoderine.
Figs 17-19 –
17,
Macrolenes dentipes
, hatching first instar larva; 18, first instar larva; 19, head of the first instar larva, frontal view.
In our study area a massive population of
M. dentipes
was recorded in
May 2019
. Adults were observed on several plants (
Arbutus firstly unedo
,
Olea europaea
,
Pistacia lentiscus
,
Vitis vinifera
), but they produced severe damages mostly on lentisk (Figs 12-13). Mating (Fig. 14) and egg clusters (Fig. 15) were observed mostly on olive tree leaves. Eggs (Fig. 16) are subcylindrical, basally pointed and distally trunked,
0.7-0.9 mm
in length and
0.4 mm
in width. The diameter of the egg distal end is about as that of the head of the first emerging larva of the leaf beetle (
0.3 mm
). The chorion of the egg is coated with brown material. The number of eggs/cluster varied from 4 to 38 (average: 18; SD ± 10.6, n = 23). The eggs hatched at the beginning of June (Fig. 17); after hatching, they showed the distal cap completely detached (Fig. 11). The first instar larva (Fig. 18),
0.8-0.9 mm
in length, is typically J-shaped, with the last abdominal segments directed ventrally. The head chaetotaxy (Fig. 19) offers diagnostic characters for the identification of the species; in particular: the single seta, on each side of the epicranial suture, not simple but at least slightly spiny as the other dorsal epicranial setae, except the very long 3
rd
seta; all frontal setae moderately or densely spiny, with the 3
rd
pair not longer than the second one.In the key for the identification of the clytrine genera by
Wasowska (2007)
, based on the first instar larva, the larva of
M. dentipes
runs near
Lobidostomis
, having one seta on each side of epicranial suture, on top of the head, but simple in the latter species, not spiny.