Mites of the genus Pyemotes are important as: 1) predators of various insects, 2) have medical importance to man and 3) have unusual life histories and morphologies (Cross and Moser, 1975). Two species groups of Pyemotes are recognized a) scolyti group; including P. scolyti (Oudemans), P. parviscolyti Cross and Moser and P. dimorphus Cross and Moser b) ventricosus group; containing the rest of the species (Cross et al., 1981).
Most members of both groups have wide-spread geographic distributions and many species of both groups are cosmopolitan. Some species of the ventricosus group are documented to possess venom, attack many host species, but are recorded most frequently with stored grain insects, or in laboratory insect cultures (Cross and Moser, 1975). In contrast, members of the scolyti group are only associated with various bark beetle species. No species of the scolyti group are known to attack adults; whereas at least some species of the ventricosus group do so regularly. For this reason, phoretic adult females of scolyti called phoretomorphs, ride their host beetles without harming them. The phoretomorphic female is a specialized stage designed for phoresy in pyemotids and some related families. The phoretomorph claw on leg 1 is very large and their body form is much more compact and sclerotized than the normal form (Cross and Moser, 1975).
Pyemotes of the ventricosus group, such as Pyemotes herfsi
(Oudemans) (P. zwoelferi Krczal) and Pyemotes tritici (Lagreze-Fossat
and Montane) (P. ventricosus (Newport) are not known to be phoretic and
do not possess phoretomorphs. Both of these species are common in Turkey. Pyemotes
herfsi was reported to prey on young larvae of Euproctis chrysorrhoea
L. (Lep.: Lymantriidae) on fruit trees in Aegean Region (Turkey) (Öncüer
et al., 1977) Pyemotes tritici was found on parasitoid of
Callosobruchus maculatus L. (Col.: Bruchidae) in stored products in Southeast
Anatolia Regions (Özer and Yücel, 1989) and on Pectinophora gossypiella
Saunders (Lep: Gelechiidae) in cotton in Aegean Region (Turkey) (Kavut
et al., 1974). Also, Pyemotes sp. was observed in stored products
in Izmir (Özer et al., 1989) and attacking thrips in vegetable areas
of Sanlüurfa (Cikman et al., 1996).
Pyemotes johnmoseri, a member of the scolyti group, is a new record for the mite fauna of Turkey and was found attacking Hypoborus ficus (Erichson) (Col.: Scolytidae) and Hesperophanes griseus Fab. (Col.: Cerambycidae) in Aydün, Turkey in 2003-2004.
Materials and Methods
The mite samples were preserved in 70% ethyl alcohol. After cleaning the mite
samples in lactophenol solutions, they were mounted in Hoyers medium.
Identification was done by A.A. Khaustov (Department of Agroecology, Nikita
Botanical Gardens National Scientific Center, Yalta 98648, Crimea, Ukraine).
All measurements are given in micrometers (μm). The terminology used in
the description follows that of Lindquist (1986). The samples have been deposited
in the collection of the senior author in University of Adnan Menderes, Plant
Protection Department, Aydün.
Pyemotes (Amerling, 1982)
Pyemotes females are parasitoids of all developmental stages of holometabolous
insects, especially on those of subcortical beetles and stored product insects.
When the female sucks the haemolymph of the host, her posterior opisthosoma
becomes greatly swollen due to developing eggs (physogastric female) (Fig.
1) (Moser et al., 1987). The distended opisthosoma of the physogastric
female may produce over 200 offspring, most of which are females; males remain
in the vicinity to fertilize emerging females (Hoschele and Tanigoshi, 1993).
Eggs hatch within the female. Males are born first, sequentially piercing the
swollen opisthosoma of their mother with their mouthparts for sustenance and
then remain situated above the opening of the birth canal. Here they use their
modified legs 4 to assist with the birth of the females, copulating with each
as they emerge. Copulation triggers searching behavior in females, which immediately
leave the area to attack a suitable host (Moser et al., 1978).
Pyemotes johnmoseri (Khaustov, 2004)
Synonyms: Pyemotes moseri (Khaustov, 1998)
Pyemotes moseri was described by Khaustov (1998) associated with Hypoborus
ficus (Col.: Scolytidae) from Ukraine. The name was preoccupied by Pyemotes
moseri (Yu and Liang, 1996). Therefore, according to article 52 of the International
Code of Zoological Nomenclature (Anonymous, 1999), Khaustov (Khaustov, 2004)
proposed a new replacement name for Pyemotes moseri (Khaustov, 1998)
as Pyemotes johnmoseri (Khaustov, 2004).
Body: Length 281 (238-350); width 76 (63-100) (Fig. 2).
Gnathosoma: Length 28 (25-33); width 25 (23-28).
Propodosoma longer than width and with four pairs of setae; sc1
oval and a cup-shaped pseudostigma; sc2 longest and plumose; v1
longer than v2. Hysterosoma includes four dorsal plates.
||Physogastric females of Pyemotes johnmoseri
|| Female of Pyemotes johnmoseri
||Pyemotes johnmoseri: male; a) ventral view, b) solenidion tibia I, c) without solenidion tibia IV
||a) Egg of Hypoborus ficus killed by Pyemotes johnmoseri b) Undamaged egg
||Larva of Hesperophanes griseus killed by Pyemotes
Setae c2 slightly longer than c1 and placed on plate C. Plate D, includes one pair of setae (d) and one pair of cupules (ia). Plates EF, with two pairs of setae (ef) and one pair of cupules (im); setae e about 1/5 as long as setae f. The tip of setae f longer posterior margin of hysterosoma. Plate H with two pairs of setae; setae h1 almost twice length h2. Lengths of dorsal setae; v1 9 (6-11), v2 7 (6-8), sc1 18 (15-20), sc2 61 (53-66), c1 25 (21-27), c2 26 (20-35), d 19 (15-22), e 10 (8-12), f 52 (42-65), h1 20 (15-25), h2 10 (7-13).
Ventrum: Apodeme I-II obvious and connecting with anterior sternal apodeme. Apodeme III-IV obvious. Setae 3a longer than 3b. The length of ventral setae: 1a 7 (4-9), 1b 6 (4-8), 2a 9 (6-13), 2b 9 (6-12), 3a 17 (10-22), 3b 9 (6-12), 3c 11 (8-12), 4a 12 (6-15), 4b 15 (12-20).
Legs: Leg I 91 (85-100) long, sturdy and with one strong claw. Tarsus I with a solenidion. Tibia I with two solenidia. Leg II 60 (55-63), III 82 (65-88) and IV 90 (79-105 long, each with a pair of small claws and a long median empodium.
Body: Length 139 (128-153); width 106 (88-125) (Fig. 3a).
Gnathosoma: Length 21 (18-23); width 25 (23-30).
Dorsum: Propodosoma almost square shaped, with four pairs of setae. Setae v1
and v2 very short. Setae sc1 almost reach the margin of
propodosoma. Hysterosoma dorsally with three plates. Plate CD separate and distinct.
Setae c1 longer than setae c2 and setae e longest. Plates
EF small with two pairs of setae. Lengths of dorsal setae; c1 17
(12-20), c2 14 (7-17), d 127 (100-180), e 135 (81-180), f 104 (70-150).
Ventrum: Apodeme I-V obvious. Apodeme I and II connecting with anterior sternal apodeme. Lengths of ventral setae; 1a 6 (2-10), 1c 4 (2-6), 2a 14 (12-17), 2c 7 (4-14), 3a 4 (4-4), 3b 10 (6-12), 3c 15 (12-17), 4a 14 (7-25), 4b 7 (3-14).
Legs: Leg I 59 (45-75), II 63 (55-70), III 118 (100-155) and IV 127 (108-170) have very strong hook-shaped claw. Tibia I with a solenidion (Fig. 3b). Tibia IV without a solenidion (Fig. 3c).
Incirliova-Aydin, 22.02.2003 (5♀, 2♂) 27.06.2003 (15♀,
5♂), 23.09.2003 (2♀, 3♂), 06.10.2003 (7♀, 2♂),
20.02.2004 (6♀, 2♂), 18.06.2004 (5♀, 1♂), 17.07.2004
(20♀, 6♂), 18.08.2004 (10♀, 4♂), 15.09.2004 (12♀,
5♂) on Hypoborus ficus and 12.06.2004 (2♀, 5♂) Hesperophanes
griseus in fig trees.
In Aydin, we observed that P. johnmoseri was widespread in fig trees
during 2003-2004 and that it fed on eggs (Fig. 4), larvae
and pupae of H. ficus. In subsequent surveys, it was also found on fig
trees as a parasitoid of a few larvae of Hesperophanes griseus (Col.:
Cerambycidae) (Fig. 5). Some members of the scolyti
group are specific to flying adults of a single species, whereas others, such
as Pyemotes scolyti are specific to flying adults within a single genus.
It is important to note here that specific refers only to the phoretic host
range and not to the range of insects that Pyemotes females will attack,
which often is quite large. At this time the phoretic host range of P. johnmoseri
is unknown except for that of flying adults of H. ficus (Cross et
al., 1981; Moser et al., 1978). Hence, at this writing it is unknown
if P. johnmoseri is truly phoretic on H. griseus, or if the mite
accidentally happened to crawl from galleries of H. ficus, into the galleries
of H. griseus, where the parasitoids attacked and developed on the brood
of H. griseus.
Ukraine (Khaustov, 1998).
Pyemotes johnmoseri is very similar to P. scolyti. P. johnmoseri differs from P. scolyti in that P. johnmoseri lacks a solenidion on the male tibia IVi (Khaustov, 1998). P. johnmoseri was first collected in the Ukraine associated with Hypoborus ficus. All of Khostovs measurements are in agreement with our material from Turkey.
Most of Pyemotes species have high reproductive capacity, short life-cycle and, due to all the development stages that occur within the mothers ophisthosomal sac, they dont need any intermediate hosts or alternate food source. All offspring are born as sexually mature adults. Only females are parasitoids and represent about 90-95% of the mite progeny. Females mate immediately at birth, begin host-seeking activity and their populations are easily reared in the laboratory condition (Bruce, 1989). For this reason, their potential for biological control on insects has recently been investigated. Although pyemotid mites of the venticosus group can cause severe dermatitis on people, some species e.g., Pyemotes tritici belonging to the ventricosus group, have shown potential as a biological control agent for a number of different insects (Bruce and Wrensch, 1990). However, P. johnmoseri, which belongs to the scolyti group, has no such toxic effects. The phoretic mite guilds associated with the various fig beetles should be investigated in further studies by trapping of flying beetles in fig orchards.
We are mostly indebted to Klaus Liebenow (Scolytidae), Pierre Teocchi (Cerambycidae) Alexander Khaustov and John Moser (Pyemotidae) for identifications and John Moser for comments on a previous version of this manuscript.